Alimentação e fecundidade de planorbídeos criados em laboratórios: IV - Helisoma duryi (Wetherby, 1879. (Pulmonata, Planorbidae Feeding and fecundity of planorbidae bred in the laboratory: IV - Helisoma duryi (Wetherby, 1879. (Putmonata, Planorbidae

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Roberto Milward-de-Andrade

1978-03-01

Full Text Available Utilizando dois tipos distintos de alimentos: "Aquariol" (alimento utilizado para alimentar peixes ornamentais e alface, isolados e associados, na criação de Helisoma (Seminolina duryi (Wetherby, 1879 em laboratório, foi verificado que; 1. Os caramujos alimentados com alface fresca liberaram, em 17 semanas, 826 desovas on 17.707 ovos. 2. Os especimens alimentados com "aquariol" depuseram 534 desovas on 11.361 ovos. 3. O oferecimento dos dois materiais associados resultou no aumento da fertilidade, obtendo-se, assim, 1.355 desovas ou 34.645 ovos. 4. Em termos médios, cada conjunto de quinze exemplares (com 10 a 14 mm de diâmetro liberou, diariamente, 95,5 - 148,8 e 291,1 ovos/dia, segundo o tipo de alimento consumido: "aquariol", alface fresca, ou ambos associados. O número de desovas/dia, na mesma ordem enunciada, foi de 4,5 - 6,9 e 11,4, respectivamente. 5, Os exemplares utilizados descendiam de uma cepa supostamente recém introduzida no município de Formosa, GO (Brasile originária da Região Neártica (EUA. Foi comentada a possibilidade de controle biológico de diferentes espécies de Biomphalaria através de H. duryi - questão sobre a qual vêm desenvolvendo investigações biológicas e ecológicas.After experiments with two types of food, lettuce and "aquariol" (i.e., animal protein flour for ornamental fish both isolated and in association, in the breeding of Helisoma (Seminolina duryi (Wetherby, 1879, the following results: were obtained: 1. Snails fed on fresh lettuce yielded, at the end of 17 weeks, 826 egglavings or, better, 17,707 eggs. 2. Specimens fed on "aquariol" produced 534 egg clutches or 11,361 eggs. 3. Snails fed on both fresh lettuce and "aquariol" happened to provide 1,355 egglayings or 34,645 eggs. 4. On the average, each batch of 15 snails or three group of 5 ones (each specimen displyaing 10-14 mm diameter liberated 95.5, 148.8 and 291.1 eggs/day, in accordance with their type of meal - lettuce, "aquariol" or

Studies on the physiology and endocrinology of reproduction of Helisoma duryi (Mollusca: Pulmonata)

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Miksys, S.L.

1987-01-01

Helisoma duryi is a hermaphroditic, freshwater, pulmonate snail native to North America. It has been proposed as a biological control agent against snail intermediate hosts of Schistosoma sp., a parasitic trematode in man. Very little is known of the physiology and endocrinology of reproduction of H. duryi. This thesis investigates vitello-genesis, endocrine control of the synthesis of albumen, a nutrient-rich fluid catabolized by developing embryos, and the possible endocrine role of the gonad. Light and electron microscopy, chemical extraction, energy dispersive X-ray analysis, and radioimmunoassay are used to identify the yolk protein ferritin. It is proposed that ferritin synthesis, and its circulating levels, are regulated, probably indirectly, by a gonadal factor released into the blood. The rate of synthesis of albumen polysaccharides can be monitored in vitro by providing albumen gland explants with the precursor /sup 14/C-glucose and measuring /sup 14/C-polysaccharide produced. The basal synthetic activity of the gland reflects the reproductive activity of the snail.

A bird's eye survey of Central American planorbid molluscs.

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Paraense, W Lobato

2003-01-01

In the course of two trips to Central America (June 1967 and JulyAugust 1976) I had the opportunity of collecting topotypic specimens of Planorbis nicaraguanus Morelet, 1849, anatomically defined in this paper, and of P. yzabalensis Crosse & Fischer, 1879, the identity of the latter with Drepanotrema anatinum (Orbigny, 1835) is confirmed. The following planorbid species were also found: Helisoma trivolvis (Say, 1817) in Nicaragua, Guatemala, Costa Rica and Belize; H. duryi (Wetherby, 1879) in Costa Rica; Biomphalaria helophila (Orbigny, 1835) in Guatemala, Belize, Nicaragua, Costa Rica and El Salvador; B. kuhniana (Clessin, 1883) in Panama; B. obstructa (Morelet,1849) in Guatemala, Belize and El Salvador; B. straminea (Dunker, 1848) in Costa Rica; B. subprona (Martens, 1899) in Guatemala; D. anatinum (Orbigny,1835) in Belize, Guatemala, Nicaragua and Costa Rica; D. depressissimum (Moricand,1839) in Nicaragua, Costa Rica and Panama; D. lucidum (Pfeiffer, 1839) in Guatemala, Belize and Nicaragua; D. surinamense (Clessin, 1884) in Costa Rica and Panama; and Gyraulus percarinatus sp. n. in Panama. The occurrence of B. kuhniana and D. surinamense is first recorded in Central America, and Gyraulus percarinatus is the first representative of the genus provenly occurring in the American continent south of the United States. The following synonymy is proposed: Planorbis declivis Tate, 1870 = Biomphalaria helophila (Orbigny, 1835); Planorbis isthmicus Pilsbry, 1920 = Biomphalaria kuhniana (Clessin, 1883); Planorbis cannarum Morelet, 1849 and Segmentina donbilli Tristram, 1861 = Biomphalaria obstructa (Morelet, 1849); and Planorbis yzabalensis Crosse & Fischer, 1879 = Drepanotrema anatinum (Orbigny, 1835), confirming Aguayo (1933).

Possible competitive displacement of planorbids by Melanoides tuberculata in Minas Gerais, Brazil

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Carlos Tito Guimarães

2001-09-01

Full Text Available Several species of snails, including Pomacea haustrum, Marisa cornuarietis and Helisoma duryi, have been identified as probable competitors and/or predators of planorbid intermediate hosts of Schistosoma. During the last few years, studies carried out in the Caribbean region have shown reductions and even disappearances of populations of Biomphalaria glabrata and B. straminea in breeding places where the snail Melanoides tuberculata was introduced. Observations made over a period of 10 years in two lakes close to Belo Horizonte, MG, showed that there were marked reductions in autochthonous populations of B. glabrata and B. straminea after the arrival of M. tuberculata, both Biomphalaria species disappearing completely after eight years.

Possible competitive displacement of planorbids by Melanoides tuberculata in Minas Gerais, Brazil.

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Guimarães, C T; Souza, C P; Soares Dd

2001-01-01

Several species of snails, including Pomacea haustrum, Marisa cornuarietis and Helisoma duryi, have been identified as probable competitors and/or predators of planorbid intermediate hosts of Schistosoma. During the last few years, studies carried out in the Caribbean region have shown reductions and even disappearances of populations of Biomphalaria glabrata and B. straminea in breeding places where the snail Melanoides tuberculata was introduced. Observations made over a period of 10 years in two lakes close to Belo Horizonte, MG, showed that there were marked reductions in autochthonous populations of B. glabrata and B. straminea after the arrival of M. tuberculata, both Biomphalaria species disappearing completely after eight years.

Effects of acute and chronic exposure to lead on the behavior of the pond snail Helisoma trivolvis

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Bennett, V.T.; Copeland, J. [Georgia Southern Univ., Statesboro, GA (United States)

1997-09-01

The behavior of aquatic invertebrates may be useful as an indicator for the presence of toxicants in both freshwater and marine environments. The pond snail Helisoma trivolvis, the red ram`s horn, was exposed to low levels of lead (0.05 ppm). Chronic exposure significantly reduced the number of head movements but had no affect on radula movement or antenna twitches. Acute exposure resulted in curling of the foot that lasted 0.5 to 14.0 minutes. Electrochemical analysis of lead levels within treated snails indicated a higher concentration of lead in the tissue than that in the treated environment. Organ analysis of the digestive gland, 1 salivary gland, reproductive organs and the cerebral ganglion is currently being studied.

Dopamine suppresses neuronal activity of Helisoma B5 neurons via a D2-like receptor, activating PLC and K channels.

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Zhong, L R; Artinian, L; Rehder, V

2013-01-03

Dopamine (DA) plays fundamental roles as a neurotransmitter and neuromodulator in the central nervous system. How DA modulates the electrical excitability of individual neurons to elicit various behaviors is of great interest in many systems. The buccal ganglion of the freshwater pond snail Helisoma trivolvis contains the neuronal circuitry for feeding and DA is known to modulate the feeding motor program in Helisoma. The buccal neuron B5 participates in the control of gut contractile activity and is surrounded by dopaminergic processes, which are expected to release DA. In order to study whether DA modulates the electrical activity of individual B5 neurons, we performed experiments on physically isolated B5 neurons in culture and on B5 neurons within the buccal ganglion in situ. We report that DA application elicited a strong hyperpolarization in both conditions and turned the electrical activity from a spontaneously firing state to an electrically silent state. Using the cell culture system, we demonstrated that the strong hyperpolarization was inhibited by the D2 receptor antagonist sulpiride and the phospholipase C (PLC) inhibitor U73122, indicating that DA affected the membrane potential of B5 neurons through the activation of a D2-like receptor and PLC. Further studies revealed that the DA-induced hyperpolarization was inhibited by the K channel blockers 4-aminopyridine and tetraethylammonium, suggesting that K channels might serve as the ultimate target of DA signaling. Through its modulatory effect on the electrical activity of B5 neurons, the release of DA in vivo may contribute to a neuronal output that results in a variable feeding motor program. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Development of Helisoma trivolvis pond snails as biological samplers for biomonitoring of current-use pesticides.

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Morrison, Shane A; Belden, Jason B

2016-09-01

Nontarget aquatic organisms residing in wetlands are commonly exposed to current-use pesticides through spray drift and runoff. However, it is frequently challenging to measure exposure because of rapid dissipation of pesticides from water and reduced bioavailability. The authors' hypothesis is that freshwater snails can serve as bioindicators of pesticide exposure based on their capacity to passively accumulate tissue residues. Helisoma trivolvis snails were evaluated as biomonitors of pesticide exposure using a fungicide formulation that contains pyraclostrobin and metconazole and is frequently applied to crops surrounding depressional wetlands. Exposure-response studies indicate that H. trivolvis are tolerant of pyraclostrobin and metconazole at concentrations >10 times those lethal to many aquatic species, with a median lethal concentration based on pyraclostrobin of 441 μg/L (95% confidence interval of 359-555 μg/L). Bioconcentration factors ranged from 137 mL/g to 211 mL/g and from 39 mL/g to 59 mL/g for pyraclostrobin and metconazole, respectively. Elimination studies suggested one-compartmental elimination and snail tissue half-lives (t50 ) of approximately 15 h and 5 h for pyraclostrobin and metconazole, respectively. Modeling derived toxicokinetic parameters in the context of an environmentally relevant pulsed exposure suggests that residues can be measured in snails long after water concentrations fall below detection limits. With high fungicide tolerance, rapid accumulation, and slow elimination, H. trivolvis may be viable for biomonitoring of pyraclostrobin and should be investigated for other pesticides. Environ Toxicol Chem 2016;35:2320-2329. © 2016 SETAC. © 2016 SETAC.

Quantitative estimation of the cost of parasitic castration in a Helisoma anceps population using a matrix population model.

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Negovetich, N J; Esch, G W

2008-10-01

Larval trematodes frequently castrate their snail intermediate hosts. When castrated, the snails do not contribute offspring to the population, yet they persist and compete with the uninfected individuals for the available food resources. Parasitic castration should reduce the population growth rate lambda, but the magnitude of this decrease is unknown. The present study attempted to quantify the cost of parasitic castration at the level of the population by mathematically modeling the population of the planorbid snail Helisoma anceps in Charlie's Pond, North Carolina. Analysis of the model identified the life-history trait that most affects lambda, and the degree to which parasitic castration can lower lambda. A period matrix product model was constructed with estimates of fecundity, survival, growth rates, and infection probabilities calculated in a previous study. Elasticity analysis was performed by increasing the values of the life-history traits by 10% and recording the percentage change in lambda. Parasitic castration resulted in a 40% decrease in lambda of H. anceps. Analysis of the model suggests that decreasing the size at maturity was more effective at reducing the cost of castration than increasing survival or growth rates of the snails. The current matrix model was the first to mathematically describe a snail population, and the predictions of the model are in agreement with published research.

How Autism Affects Speech Understanding in Multitalker Environments

Science.gov (United States)

2015-12-01

Allen, Cleary, Kublin, & Goldstein , 2002; Wetherby, Goldstein , Cleary, Allen, & Kublin, 2003; Wetherby & Prizant, 1993; Wetherby, Watt, Morgan...functioning individuals with autism or Asperger’s syndrome. Journal of Child Psychology and Psychiatry, 45(6), 1107-1114. Barker, B. A., & Newman, R...S. (2004). Listen to your mother! The role of talker familiarity in infant streaming. Cognition , 94(2), B45-B53. Bricker, D., Squires, J., Mounts

Invading freshwater snails and biological control in Martinique Island, French West Indies.

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Pointier, J P

2001-01-01

Eight alien freshwater snail species were introduced into Martinique Island during the last 50 years. The introduced snails include four planorbids (Biomphalaria straminea, Helisoma duryi, Amerianna carinata and Gyraulus sp.), three thiarids (Melanoides tuberculata, M. amabilis and Tarebia granifera) and one ampullarid (Marisa cornuarietis). Four of these species rapidly colonized the whole Martinican hydrographic system whereas the other four remained restricted to some particular sites. The invasion processes were documented during the last 20 years and showed (i) a rapid invasion of the island by several morphs of M. tuberculata at the beginning of the 80's; (ii) the introduction of T. granifera in 1991 and M. amabilis in 1997; and (iii) the rapid spread of these last two species throughout the island. In the years following its introduction, M. tuberculata was used in biological control experiments against the snail hosts of schistosomiasis, B. glabrata and B. straminea. Experiments were conducted with success in several groups of water-cress beds which constituted the latest transmission sites for schistosomiasis at the beginning of the 80's. A malacological survey carried out in 2000 all over the island showed the absence of B. glabrata but the presence of some residual populations of B. straminea. Long-term studies carried out in Martinique have shown that the thiarids are able to maintain relatively stable populations over a long period of time, thus preventing recolonization by the snail hosts. Within this context the invasion of the hydrographic system of Martinique by thiarid snails has resulted in an efficient and sustainable control of the intermediate hosts of schistosomiasis.

Invading freshwater snails and biological control in Martinique Island, French West Indies

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Jean-Pierre Pointier

2001-09-01

Full Text Available Eight alien freshwater snail species were introduced into Martinique Island during the last 50 years. The introduced snails include four planorbids (Biomphalaria straminea, Helisoma duryi, Amerianna carinata and Gyraulus sp., three thiarids (Melanoides tuberculata, M. amabilis and Tarebia granifera and one ampullarid (Marisa cornuarietis. Four of these species rapidly colonized the whole Martinican hydrographic system whereas the other four remained restricted to some particular sites. The invasion processes were documented during the last 20 years and showed (i a rapid invasion of the island by several morphs of M. tuberculata at the beginning of the 80's; (ii the introduction of T. granifera in 1991 and M. amabilis in 1997; and (iii the rapid spread of these last two species throughout the island. In the years following its introduction, M. tuberculata was used in biological control experiments against the snail hosts of schistosomiasis, B. glabrata and B. straminea. Experiments were conducted with success in several groups of water-cress beds which constituted the latest transmission sites for schistosomiasis at the beginning of the 80's. A malacological survey carried out in 2000 all over the island showed the absence of B. glabrata but the presence of some residual populations of B. straminea. Long-term studies carried out in Martinique have shown that the thiarids are able to maintain relatively stable populations over a long period of time, thus preventing recolonization by the snail hosts. Within this context the invasion of the hydrographic system of Martinique by thiarid snails has resulted in an efficient and sustainable control of the intermediate hosts of schistosomiasis.

The Role of Spatial and Temporal Heterogeneity and Competition In Structuring Trematode Communities In the Great Pond Snail, Lymnaea stagnalis (L.)

Czech Academy of Sciences Publication Activity Database

Soldánová, Miroslava; Kuris, A. M.; Scholz, Tomáš; Lafferty, K. D.

2012-01-01

Roč. 98, č. 3 (2012), s. 460-471 ISSN 0022-3395 R&D Projects: GA ČR GAP505/10/1562; GA ČR GD206/09/H026; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : LARVAL TREMATODES * HELISOMA-ANCEPS * INTERSPECIFIC INTERACTIONS * DIPLOSTOMUM-SPATHACEUM * CENTRAL-EUROPE * ANTAGONISM * PARASITES * HOST * PATTERNS * DYNAMICS Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.321, year: 2012

Operation & Maintenance Environmental Impact Statement for the Federal Facilities at Sault Ste. Marie, Michigan, Addressing Limited Season Extension of Operation. Supplement.

Science.gov (United States)

1979-10-01

azteca Aca r ina I sopoda Ar renur us Asellus Lirceus Castropoda Anic ola Diptera Campe loma Tipulidae (S) Gyraulus Ceratopogonidae Helisoma...turbidity could affect the primary productivity in the area for a brief period. Solar energy entering a body of water is converted by microscopic...8217. 4 U 0 Cd co m4 Z i C4 i dio C. ’. U ’U d 0 . C dd W 𔃾 Cd 4 d d > d - U 0 - C ’. i d . - d 44tl n C> - _4 In 0 0 -d W - C C. U : A i ’U 0 di -0 A

Bioaccumulation of sup(95m)Tc in fish and snails

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Blaylock, B.G.; Frank, M.L.; DeAngelis, D.L. (Oak Ridge National Lab., TN (USA))

1982-03-01

Concentration factors for technetium recommended in radiological assessment models for freshwater biota are default values based on the behavior of iodine in the environment. A small experimental freshwater pond was spiked with sup(95m)Tc to obtain data for calculating concentration factors for fish and snails. A model using the pond data was developed to calculate steady-state body burdens for freshwater biota. The concentration factors based on the calculated body burden for carp (Caprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 11,75 and 121, respectively. The concentration factor for carp was less than the recommended value of 15 listed in the USNRC Regulatory Guide 1.109 for calculating radiation dose to man; however, the concentration factors for mosquitofish and snails exceeded the recommended values by 5 and 25 times, respectively.

Bioaccumulation of /sup 95m/Tc in fish and snails

Energy Technology Data Exchange (ETDEWEB)

Blaylock, B.G.; Frank, M.L.; DeAngelis, D.L.

1982-03-01

Concentration factors for technetium recommended in radiological assessment models for freshwater biota are default values based on the behavior of iodine in the environment. In this study a small experimental freshwater pond was spiked with /sup 95/mTc to obtain data for calculating concentration factors for fish and snails. A model using the pond data was developed to calculate steady-state body burdens for freshwater biota. The concentration factors based on the calculated body burden for carp (Caprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 11, 75 and 121, respectively. The concentration factor for carp was less than the recommended value of 15 listed in the USNRC Regulatory Guide 1.109 for calculating radiation dose to man; however, the concentration factors for mosquitofish and snails exceeded the recommended values by 5 and 24 times, respectively.

Preference of redear sunfish on zebra mussels and rams-horn snails

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French, John R. P.; Morgan, Michael N.

1995-01-01

We tested prey preferences of adult (200- to 222-mm long) redear sunfish (Lepomis microlophus) on two size classes of zebra mussels (Dreissena polymorpha) and two-ridge rams-horns (Helisoma anceps) in experimental aquaria. We also tested physical limitations on consuming these mollusks and determined prey bioenergetic profitability. Redear sunfish strongly preferred rams-horns over zebra mussels, but they displayed no size preference for either prey. Ingestion was not physically limited since both prey species up to 15-mm long fit within the pharyngeal gapes of redear sunfish. Rams-horns were more bioenergetically profitable than zebra mussels and ingestion of rams-horn shell fragments was about three times less than zebra mussels. Rams-horns were somewhat more resistant to shell-crushing, but all size ranges of both prey species tested were crushable by redear sunfish. These studies suggested that the redear sunfish should not be considered a panacea for biological control of zebra mussels.

The relationship between prelinguistic vocalization and later expressive vocabulary in young children with developmental delay.

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McCathren, R B; Yoder, P J; Warren, S F

1999-08-01

This study tested the relationship between prelinguistic vocalization and expressive vocabulary 1 year later in young children with mild to moderate developmental delays. Three vocalization variables were tested: rate of all vocalization, rate of vocalizations with consonants, and rate of vocalizations used interactively. The 58 toddlers in the study were 17-34 months old, not sensory impaired, and had Bayley Mental Development Indices (Bayley, 1969; Bayley, 1993) from 35-85. In addition, the children had fewer than 3 words in their expressive vocabularies and during classroom observation each showed at least one instance of intentional prelinguistic communication before testing. Selected sections of the Communication and Symbolic Behavior Scales procedures (CSBS; Wetherby & Prizant, 1993) were administered at the beginning and at the end of the study. The vocal measures were obtained in the initial CSBS session. One measure of expressive vocabulary was obtained in the CSBS session at the end of the study. In addition, expressive vocabulary was measured in a nonstructured play session at the end of the study. We predicted that rate of vocalization, rate of vocalizations with consonants, and rate of vocalizations used interactively would all be positively related to later expressive vocabulary. The results confirmed the predictions.

Repetitive and stereotyped movements in children with autism spectrum disorders late in the second year of life.

Science.gov (United States)

Morgan, Lindee; Wetherby, Amy M; Barber, Angie

2008-08-01

The purpose of this study was to examine group differences and relationships with later developmental level and autism symptoms using a new clinical tool developed to measure repetitive and stereotyped movements (RSM) in young children. Videotaped behavior samples using the Communication and Symbolic Behavior Scales Developmental Profile (CSBS; Wetherby & Prizant, 2002) were coded for children with autism spectrum disorders (ASD; n = 50), developmental delays without ASD (DD; n = 25), and typical development (TD; n = 50) between 18 and 24 months of age. Children with ASD demonstrated significantly higher rate and larger inventory of RSM with objects and body during a systematic behavior sample than both the DD and TD groups. Measures of RSM were related to concurrent measures of social communication and predicted developmental outcomes and autism symptoms in the fourth year for the ASD group. None of the correlations between RSM and autism symptoms remained significant when controlling for CSBS Symbolic level. RSM with objects predicted unique variance in the severity of autism symptoms in the fourth year beyond that predicted by social communication measures alone. This study provides support for the diagnostic significance of RSM in children under 24 months of age and documents the utility of this RSM measurement tool as a companion to the CSBS.

Self-recognition: a constraint on the formation of electrical coupling in neurons.

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Guthrie, P B; Lee, R E; Rehder, V; Schmidt, M F; Kater, S B

1994-03-01

Electrical coupling between specific neurons is important for proper function of many neuronal circuits. Identified cultured neurons from the snail Helisoma show a strong correlation between electrical coupling and presence of gap junction plaques in freeze-fracture replicas. Gap junction plaques, however, were never seen between overlapping neurites from a single neuron, even though those same neurites formed gap junctions with neurites from another essentially identical identified neuron. This observation suggests that a form of self-recognition inhibits reflexive gap junction formation between sibling neurites. When one or both of those growth cones had been physically isolated from the neuronal cell body, both electrical coupling and gap junction plaques, between growth cones from the same neuron, were observed to form rapidly (within 30 min). Thus, inhibition of electrical coupling between sibling neurites apparently depends on cytoplasmic continuity between neurites, and not the molecular composition of neurite membrane. The formation of gap junctions is not likely due to the isolation process; rather, the physical isolation appears to release an inhibition of reflexive gap junction formation. These data demonstrate the existence of a previously unknown constraint on the formation of electrical synapses.