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Nagahama T, Nakajima H, Wakuta M, Kasahara Y, Narita K, Nagahama S. Administration of amyloid-β oligomer to the buccal ganglia may reduce food intake and cholinergic synaptic responses within the feeding neural circuit in Aplysia kurodai. Neurosci Res 2023; 196:32-39. [PMID: 37328111 DOI: 10.1016/j.neures.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/23/2023] [Accepted: 06/11/2023] [Indexed: 06/18/2023]
Abstract
Anorexia is a behavioral change caused by functional brain disorders in patients with Alzheimer's disease (AD). Amyloid-β (1-42) oligomers (o-Aβ) are possible causative agents of AD that impair signaling via synaptic dysfunction. In this study, we used Aplysia kurodai to study functional disorders of the brain through o-Aβ. Administration of o-Aβ to the buccal ganglia (feeding brain for oral movements) by surgical treatment significantly reduced food intake for at least five days. Furthermore, we explored the effects of o-Aβ on the synaptic function in the feeding neural circuit, focusing on a specific inhibitory synaptic response in jaw-closing motor neurons produced by cholinergic buccal multi-action neurons because we recently found that this cholinergic response decreases with aging, which is consistent with the cholinergic hypothesis for aging. Administration of o-Aβ to the buccal ganglia significantly reduced the synaptic response within minutes, whereas administration of amyloid-β (1-42) monomers did not. These results suggest that o-Aβ may impair the cholinergic synapses, even in Aplysia, which is consistent with the cholinergic hypothesis for AD.
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Affiliation(s)
- Tatsumi Nagahama
- Department of Biophysics, Faculty of Pharmaceutical Science, Toho University, Funabashi 274-8510, Japan; Faculty of Health and Medical Science, Teikyo Heisei University, Tokyo 170-8445, Japan.
| | - Hiroshi Nakajima
- Department of Biophysics, Faculty of Pharmaceutical Science, Toho University, Funabashi 274-8510, Japan
| | - Mizuki Wakuta
- Department of Biophysics, Faculty of Pharmaceutical Science, Toho University, Funabashi 274-8510, Japan
| | - Yuse Kasahara
- Department of Biophysics, Faculty of Pharmaceutical Science, Toho University, Funabashi 274-8510, Japan
| | - Kouki Narita
- Department of Biophysics, Faculty of Pharmaceutical Science, Toho University, Funabashi 274-8510, Japan
| | - Setsuko Nagahama
- Faculty of Health and Medical Science, Teikyo Heisei University, Tokyo 170-8445, Japan
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2
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Nagahama T, Muramatsu M, Nagahama S. An age-related decline in the cholinergic synaptic response may cause the firing pattern in the jaw-closing motor neurons, which resembles the aversive taste response in the feeding behavior of old Aplysia kurodai. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2022; 208:561-570. [PMID: 36104576 PMCID: PMC9734230 DOI: 10.1007/s00359-022-01573-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/28/2022] [Accepted: 09/01/2022] [Indexed: 12/14/2022]
Abstract
Anorexia due to aging is recognized as a syndrome of animal feeding behavior. Age-related functional disorders of the brain often cause behavioral changes. We used Aplysia kurodai to study this neural mechanism, following our previous study on food preference behaviors. The age of each wild animal was defined by a previously described method, and a significant age-related decline in food intake was observed. In this study, we explored the effects of aging on a specific inhibitory synaptic response in jaw-closing (JC) motor neurons produced by cholinergic multiaction (MA) neurons, the size of which determines the delay between MA and JC firings and this delay is reduced during aversive taste responses; in our analyses, we found a significant age-related decline in the synaptic response. Thereafter, we further explored whether such functional decline affects the JC firing pattern during the normal feeding response. During the feeding-like rhythmic responses induced by electrical nerve stimulation, the firing of the JC motor neurons advanced toward that of the MA burst, which typically happens during aversive taste responses. These results suggest that the age-related decline in the cholinergic synaptic response may partly cause the JC firing patterns that resemble the aversive taste response in old animals.
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Affiliation(s)
- Tatsumi Nagahama
- Department of Biophysics, Faculty of Pharmaceutical Science, Toho University, Funabashi, 274-8510, Japan.
- Faculty of Health and Medical Science, Teikyo Heisei University, Tokyo, 170-8445, Japan.
| | - Motohiro Muramatsu
- Department of Biophysics, Faculty of Pharmaceutical Science, Toho University, Funabashi, 274-8510, Japan
| | - Setsuko Nagahama
- Faculty of Health and Medical Science, Teikyo Heisei University, Tokyo, 170-8445, Japan
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Miller MW. Dopamine as a Multifunctional Neurotransmitter in Gastropod Molluscs: An Evolutionary Hypothesis. THE BIOLOGICAL BULLETIN 2020; 239:189-208. [PMID: 33347799 PMCID: PMC8016498 DOI: 10.1086/711293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
AbstractThe catecholamine 3,4-dihydroxyphenethylamine, or dopamine, acts as a neurotransmitter across a broad phylogenetic spectrum. Functions attributed to dopamine in the mammalian brain include regulation of motor circuits, valuation of sensory stimuli, and mediation of reward or reinforcement signals. Considerable evidence also supports a neurotransmitter role for dopamine in gastropod molluscs, and there is growing appreciation for its potential common functions across phylogeny. This article reviews evidence for dopamine's transmitter role in the nervous systems of gastropods. The functional properties of identified dopaminergic neurons in well-characterized neural circuits suggest a hypothetical incremental sequence by which dopamine accumulated its diverse roles. The successive acquisition of dopamine functions is proposed in the context of gastropod feeding behavior: (1) sensation of potential nutrients, (2) activation of motor circuits, (3) selection of motor patterns from multifunctional circuits, (4) valuation of sensory stimuli with reference to internal state, (5) association of motor programs with their outcomes, and (6) coincidence detection between sensory stimuli and their consequences. At each stage of this sequence, it is proposed that existing functions of dopaminergic neurons favored their recruitment to fulfill additional information processing demands. Common functions of dopamine in other intensively studied groups, ranging from mammals and insects to nematodes, suggest an ancient origin for this progression.
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Brown JW, Schaub BM, Klusas BL, Tran AX, Duman AJ, Haney SJ, Boris AC, Flanagan MP, Delgado N, Torres G, Rolón-Martínez S, Vaasjo LO, Miller MW, Gillette R. A role for dopamine in the peripheral sensory processing of a gastropod mollusc. PLoS One 2018; 13:e0208891. [PMID: 30586424 PMCID: PMC6306152 DOI: 10.1371/journal.pone.0208891] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 11/27/2018] [Indexed: 11/26/2022] Open
Abstract
Histological evidence points to the presence of dopamine (DA) in the cephalic sensory organs of multiple gastropod molluscs, suggesting a possible sensory role for the neurotransmitter. We investigated the sensory function of DA in the nudipleuran Pleurobranchaea californica, in which the central neural correlates of sensation and foraging behavior have been well characterized. Tyrosine hydroxylase-like immunoreactivity (THli), a signature of the dopamine synthetic pathway, was similar to that found in two other opisthobranchs and two pulmonates previously studied: 1) relatively few (<100) THli neuronal somata were observed in the central ganglia, with those observed found in locations similar to those documented in the other snails but varying in number, and 2) the vast majority of THli somata were located in the peripheral nervous system, were associated with ciliated, putative primary sensory cells, and were highly concentrated in chemotactile sensory organs, giving rise to afferent axons projecting to the central nervous system. We extended these findings by observing that applying a selective D2/D3 receptor antagonist to the chemo- and mechanosensory oral veil-tentacle complex of behaving animals significantly delayed feeding behavior in response to an appetitive stimulus. A D1 blocker had no effect. Recordings of the two major cephalic sensory nerves, the tentacle and large oral veil nerves, in a deganglionated head preparation revealed a decrease of stimulus-evoked activity in the former nerve following application of the same D2/D3 antagonist. Broadly, our results implicate DA in sensation and engender speculation regarding the foraging-based decisions the neurotransmitter may serve in the nervous system of Pleurobranchaea and, by extension, other gastropods.
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Affiliation(s)
- Jeffrey W. Brown
- Program in Biophysics and Computational Biology, University of Illinois, Urbana, Illinois, United States of America
- College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
| | - Brittany M. Schaub
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Bennett L. Klusas
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Andrew X. Tran
- School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Alexander J. Duman
- School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Samantha J. Haney
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Abigail C. Boris
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Megan P. Flanagan
- School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Nadia Delgado
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico, United States of America
| | - Grace Torres
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico, United States of America
| | - Solymar Rolón-Martínez
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico, United States of America
| | - Lee O. Vaasjo
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico, United States of America
| | - Mark W. Miller
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico, United States of America
| | - Rhanor Gillette
- Program in Biophysics and Computational Biology, University of Illinois, Urbana, Illinois, United States of America
- School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Molecular & Integrative Physiology and the Neuroscience Program, University of Illinois, Urbana, Illinois, United States of America
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Briskin-Luchinsky V, Tam S, Shabbat S, Hurwitz I, Susswein AJ. NO is required for memory formation and expression of memory, and for minor behavioral changes during training with inedible food in Aplysia. ACTA ACUST UNITED AC 2018; 25:206-213. [PMID: 29661833 PMCID: PMC5903400 DOI: 10.1101/lm.046474.117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 02/05/2018] [Indexed: 12/24/2022]
Abstract
A learning experience may lead to changes in behavior during the experience, and also to memory expressed at a later time. Are signals causing changes in behavior during the learning experience related to the formation and expression of memory? We examined this question, using learning that food is inedible in Aplysia. Treatment of an isolated buccal ganglia preparation with an NO donor elicited rejection-like motor programs. Rejection initiated by NO production is consistent with aspects of behavioral changes seen while animals learn, and with memory formation. Nonetheless, applying the NO donor during training had only minor effects on behavior during the training, and did not improve memory, indicating that the induction of rejection in the buccal ganglia is unlikely to be the means by which NO during training contributes to memory formation. Block of NO during memory retrieval prevented the expression of memory, as measured by a lack of savings in time to stop responding to food. Applying an NO donor to the cerebral ganglion while eliciting fictive feeding inhibited the expression of feeding activity, indicating that some NO effects on memory consolidation and on expression of memory may be via effects on the cerebral ganglion.
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Affiliation(s)
- Valeria Briskin-Luchinsky
- The Mina and Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, 52900, Israel
| | - Shlomit Tam
- The Mina and Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, 52900, Israel
| | - Shlomit Shabbat
- The Mina and Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, 52900, Israel
| | - Itay Hurwitz
- The Mina and Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, 52900, Israel
| | - Abraham J Susswein
- The Mina and Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, 52900, Israel
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Nagahama T, Abe R, Enomoto Y, Kashima A. Effects of aging on the food intake in the feeding behavior of Aplysia kurodai. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2016; 202:803-811. [PMID: 27604699 DOI: 10.1007/s00359-016-1122-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 08/29/2016] [Accepted: 08/29/2016] [Indexed: 11/26/2022]
Abstract
In wild Aplysia, the birthdate of animals can typically not be determined. Therefore, we sought a reliable index of old age by taking into consideration the distinguished Japanese seasons. Large amounts of eggs and dead bodies were present on the coast during and after the second half of May (MayS). Body mass decreased after May. We roughly classified animals collected before and after the MayS as mature and old animals. Plots of internalized shell length (S) against body mass (B) gave distinct best-fit curves for mature and old animals. The B/S significantly decreased in the second half of June, suggesting that body mass decreases with age but shell length is maintained in each animal. Therefore, the collected animals were classified into mature and old animals using the best-fit curves for animals classified by the collection period. We examined the amount of food intake every 2 h up to 8 h after providing food. The amounts increased linearly, and the rate was significantly lower in old animals than in mature animals. The amount of 1-day food intake was also significantly lower in old animals. These results suggest that food intake may decline with age and this may cause mass loss in old animals.
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Affiliation(s)
- Tatsumi Nagahama
- Department of Biophysics, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Japan.
| | - Risa Abe
- Department of Biophysics, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Japan
| | - Yuki Enomoto
- Department of Biophysics, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Japan
| | - Atsuhiro Kashima
- Department of Biophysics, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Japan
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7
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Vallejo D, Habib MR, Delgado N, Vaasjo LO, Croll RP, Miller MW. Localization of tyrosine hydroxylase-like immunoreactivity in the nervous systems of Biomphalaria glabrata and Biomphalaria alexandrina, intermediate hosts for schistosomiasis. J Comp Neurol 2014; 522:2532-52. [PMID: 24477836 PMCID: PMC4043854 DOI: 10.1002/cne.23548] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 01/20/2014] [Accepted: 01/22/2014] [Indexed: 11/09/2022]
Abstract
Planorbid snails of the genus Biomphalaria are major intermediate hosts for the digenetic trematode parasite Schistosoma mansoni. Evidence suggests that levels of the neurotransmitter dopamine (DA) are reduced during the course of S. mansoni multiplication and transformation within the snail. This investigation used immunohistochemical methods to localize tyrosine hydroxylase (TH), the rate-limiting enzyme in the biosynthesis of catecholamines, in the nervous system of Biomphalaria. The two species examined, Biomphalaria glabrata and Biomphalaria alexandrina, are the major intermediate hosts for S. mansoni in sub-Saharan Africa, where more than 90% of global cases of human intestinal schistosomiasis occur. TH-like immunoreactive (THli) neurons were distributed throughout the central nervous system (CNS) and labeled fibers were present in all commissures, connectives, and nerves. Some asymmetries were observed, including a large distinctive neuron (LPeD1) in the pedal ganglion described previously in several pulmonates. The majority of TH-like immunoreactive neurons were detected in the peripheral nervous system (PNS), especially in lip and foot regions of the anterior integument. Independent observations supporting the dopaminergic phenotype of THli neurons included 1) block of LPeD1 synaptic signaling by the D2/3 antagonist sulpiride, and 2) the similar localization of aqueous aldehyde (FaGlu)-induced fluorescence. The distribution of THli neurons indicates that, as in other gastropods, dopamine functions as a sensory neurotransmitter and in the regulation of feeding and reproductive behaviors in Biomphalaria. It is hypothesized that infection could stimulate transmitter release from dopaminergic sensory neurons and that dopaminergic signaling could contribute to modifications of both host and parasite behavior.
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Affiliation(s)
- Deborah Vallejo
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
| | - Mohammed R. Habib
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada
- Theodor Bilharz Research Institute, Giza, Egypt
| | - Nadia Delgado
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
| | - Lee O. Vaasjo
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
| | - Roger P. Croll
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada
| | - Mark W. Miller
- Institute of Neurobiology and Department of Anatomy & Neurobiology, University of Puerto Rico, Medical Sciences Campus, 201 Blvd del Valle, San Juan, Puerto Rico 00901
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Narusuye K, Hamaguchi A, Nagahama T. Activity changes in jaw motor neurons induced by egg-laying hormone contribute to the feeding suppression during egg-laying behavior in Aplysia kurodai. Neurosci Res 2013; 76:31-41. [PMID: 23501243 DOI: 10.1016/j.neures.2013.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 02/26/2013] [Accepted: 03/04/2013] [Indexed: 11/19/2022]
Abstract
Egg-laying behavior in Aplysia is accompanied by behavioral changes such as feeding suppression. We investigated the effects of the egg-laying hormone (ELH) on food intake, the activity patterns of jaw muscles, and the activity of buccal neurons (multi-action neuron [MA1] and jaw-closing motor neuron [JC2]), which are elements of the feeding neural circuits controlling jaw movements in Aplysia kurodai. Injection of ELH into the body cavity inhibited the intake of seaweed. After ELH application, the rhythmic activity of jaw muscles that was induced by preferred taste stimulation elicited fewer ingestion-like responses and increased the number of rejection-like responses. ELH applied to the buccal ganglia increased the firing activity of JC2 during spontaneous rhythmic responses and during the rhythmic feeding-like responses that were evoked by electrical stimulation of the esophageal nerves. In the 2 types of rhythmic responses, the Dn (normalized value of the delay time of JC2 firing onset) decreased after ELH application as compared with the control. Furthermore, ELH decreased the size of MA1-induced inhibitory postsynaptic currents in JC2. These results suggest that ELH changes the buccal motor program from ingestion to rejection on the basis of our previous results, and may contribute to a decrease in food intake during egg laying.
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Affiliation(s)
- Kenji Narusuye
- Department of Biophysics, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan.
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9
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Nagahama T, Fujimoto K, Takami S, Kinugawa A, Narusuye K. Effective amino acid composition of seaweeds inducing food preference behaviors in Aplysia kurodai. Neurosci Res 2009; 64:243-50. [PMID: 19447292 DOI: 10.1016/j.neures.2009.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 03/02/2009] [Accepted: 03/09/2009] [Indexed: 11/20/2022]
Abstract
Aplysia kurodai feeds on Ulva but rejects Gelidium and Pachydictyon with distinct patterned jaw movements. We previously demonstrated that these movements are induced by taste alone. Thus some chemicals may contribute to induction of these responses. We explored the amino acids composition of Ulva, Gelidium and Pachydictyon extracts used during our taste-induced physiological experiments. These solutions contained many constituents. The concentrations of six amino acids (Asp, Asn, Glu, Gln, Phe, Tau) were obviously different in the three extract solutions. We explored patterned jaw movements following application of solutions containing a pure amino acid. We statistically compared the occurrence numbers of ingestion-like and rejection-like patterned jaw movements (positive and negative values, respectively) for each amino acid. Our results suggested that L-Asn tends to induce ingestion-like responses, likely resulting in a preference of Ulva. In contrast, L-Asp tends to induce rejection-like responses, likely resulting in aversion towards Pachydictyon. In addition, we demonstrated that L-Asn and L-Asp solutions were sufficient to induce muscle activity associated with ingestion-like or rejection-like responses in the jaw muscles of a semi-intact preparation.
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Affiliation(s)
- Tatsumi Nagahama
- Department of Biophysics, Faculty of Pharmaceutical Science and Open Research Center, Toho University, Funabashi, Japan.
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10
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Narusuye K, Kinugawa A, Nagahama T. Responses of cerebral GABA-containing CBM neuron to taste stimulation with seaweed extracts in Aplysia kurodai. ACTA ACUST UNITED AC 2006; 65:146-56. [PMID: 16114014 DOI: 10.1002/neu.20182] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Aplysia kurodai distributed along Japan feeds well on Ulva pertusa but rejects Gelidium amansii with distinctive patterned movements of the jaws and radula. On the ventral side of the cerebral M cluster, four cell bodies of higher order neurons that send axons to the buccal ganglia are distributed (CBM neurons). We have previously shown that the dopaminergic CBM1 modulates basic feeding circuits in the buccal ganglia for rejection by firing at higher frequency after application of the aversive taste of seaweed such as Gelidium amansii. In the present experiments immunohistochemical techniques showed that the CBM3 exhibited gamma-aminobutyric acid (GABA)-like immunoreactivity. The CBM3 may be equivalent to the CBI-3 involved in changing the motor programs from rejection to ingestion in Aplysia californica. The responses of the CBM3 to taste stimulation of the lips with seaweed extracts were investigated by the use of calcium imaging. The calcium-sensitive dye, Calcium Green-1, was iontophoretically introduced into a cell body of the CBM3 using a microelectrode. Application of Ulva pertusa or Gelidium amansii extract induced different changes in fluorescence in the CBM3 cell body, indicating that taste of Ulva pertusa initially induced longer-lasting continuous spike responses at slightly higher frequency compared with that of Gelidium amansii. Considering a role of the CBM3 in the pattern selection, these results suggest that elongation of the initial firing response may be a major factor for the CBM3 to switch the buccal motor programs from rejection to ingestion after application of different tastes of seaweeds in Aplysia kurodai.
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Affiliation(s)
- Kenji Narusuye
- Department of Life Science, Graduate School of Science & Technology, Kobe University, Kobe 657-8501, Japan
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11
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Mizunami M, Yokohari F, Takahata M. Further exploration into the adaptive design of the arthropod "microbrain": I. Sensory and memory-processing systems. Zoolog Sci 2005; 21:1141-51. [PMID: 15613794 DOI: 10.2108/zsj.21.1141] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Arthropods have small but sophisticated brains that have enabled them to adapt their behavior to a diverse range of environments. In this review, we first discuss some of general characteristics of the arthropod "microbrain" in comparison with the mammalian "megalobrain". Then we discuss about recent progress in the study of sensory and memory-processing systems of the arthropod "microbrain". Results of recent studies have shown that (1) insects have excellent capability for elemental and context-dependent forms of olfactory learning, (2) mushroom bodies, higher olfactory and associative centers of arthropods, have much more elaborated internal structures than previously thought, (3) many genes involved in the formation of basic brain structures are common among arthropods and vertebrates, suggesting that common ancestors of arthropods and vertebrates already had organized head ganglia, and (4) the basic organization of sensori-motor pathways of the insect brain has features common to that of the mammalian brain. These findings provide a starting point for the study of brain mechanisms of elaborated behaviors of arthropods, many of which remain unexplored.
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Affiliation(s)
- Makoto Mizunami
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
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Due MR, Jing J, Weiss KR. Dopaminergic contributions to modulatory functions of a dual-transmitter interneuron in Aplysia. Neurosci Lett 2004; 358:53-7. [PMID: 15016433 DOI: 10.1016/j.neulet.2003.12.058] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2003] [Revised: 11/12/2003] [Accepted: 12/12/2003] [Indexed: 11/25/2022]
Abstract
The feeding central pattern generator of Aplysia produces motor programs that can differ in the degree to which they are ingestive or egestive. A number of pattern-generating interneurons that play an important role in shaping motor programs have been identified. One of these interneurons, B65, is unusual in that it contains two classical neurotransmitters, dopamine and gamma-aminobutyric acid. Here, we study the role of one of these transmitters, dopamine, using a combination of pharmacological and electrophysiological means. We show that B65 uses dopamine to elicit fast synaptic potentials in several follower neurons. Furthermore, we demonstrate that the dopamine antagonist sulpiride mimics the effect of bilateral B65 hyperpolarization on egestive motor programs. Thus our data suggest that dopaminergic transmission serves to increase the degree of egestiveness of motor programs, and decrease the duration of the protraction phase.
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Affiliation(s)
- Michael R Due
- Department of Physiology and Biophysics, Mount Sinai School of Medicine, Box 1218, New York, NY 10029, USA
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13
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Yoshida R, Nagahama T. Search for cerebral G cluster neurons responding to taste stimulation with seaweed in Aplysia kurodai by the use of calcium imaging. JOURNAL OF NEUROBIOLOGY 2003; 55:299-314. [PMID: 12717700 DOI: 10.1002/neu.10207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The calcium imaging method can detect the spike activities of many neurons simultaneously. In the present experiments, this method was used to search for unique neurons contributing to feeding behavior in the cerebral ganglia of Aplysia kurodai. We mainly explored the neurons whose cell bodies were located in the G cluster and the neuropile region posterior to this cluster on the ventral surface of the cerebral ganglia. When the extract of the food seaweed Ulva was applied to the tentacle-lip region, many neurons stained with a calcium-sensitive dye, Calcium Green-1, showed changes in fluorescence. Some neurons showed rhythmic responses and others showed transient responses, suggesting that these neurons may be partly involved in the feeding circuits. We also identified three motor neurons among these neurons that showed rhythmic fluorescence responses to the taste stimulation. One of them was a motor neuron shortening the anterior tentacle (ATS), and the other two were motor neurons producing lip opening-like (LO(G)) and closing-like (LC(G)) movements, respectively. Application of the Ulva extract to the tentacle-lip region induced phase-locked rhythmic firing activity in these motor neurons, suggesting that these neurons may contribute to the rhythmic patterned movements of the anterior tentacles and lips during the ingestion of seaweed.
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Affiliation(s)
- Ryusuke Yoshida
- Department of Biology, Faculty of Science, Kobe University, Rokkodai, Nada-ku, Kobe 657-8501, Japan
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