Chapter 29 Egg laying in the hermaphrodite pond snail Lymnaea stagnalis

Author(s):  
Andries Ter Maat
1993 ◽  
Vol 178 (1) ◽  
pp. 251-259 ◽  
Author(s):  
G. P. Ferguson ◽  
A. W. Pieneman ◽  
R. F. Jansen ◽  
A. Ter Maat

The egg-laying behaviour of gastropod molluscs is controlled by peptidergic neuroendocrine cells and has provided an important experimental system for behavioural neurobiology. The genes that code for multiple peptides have been sequenced and the peptides themselves have been identified, thus enabling us to investigate how they act on the nervous system to produce the overt behavioural pattern (reviewed by Geraerts et al. 1988). The two animals that have been studied most extensively are the opisthobranch Aplysia californica and the pulmonate Lymnaea stagnalis. In both cases, the peptidergic neurones controlling egg laying are normally electrically silent (both in vivo and in vitro; Kupfermann, 1967; Pinsker and Dudek, 1977; Kits, 1980; Ter Maat et al. 1986) and produce multiple peptides (Rothman et al. 1983; Geraerts et al. 1985; Sigvardt et al. 1986), which are cleaved from a common protein precursor (Scheller et al. 1983; Vreugdenhil et al. 1988). Before egg laying, the cells produce a long-lasting discharge of action potentials (Pinsker and Dudek, 1977; Ter Maat et al. 1986). This electrical discharge initiates egg-laying behaviour, and during it the peptides (one of which initiates ovulation) are released into the blood. The demonstration, in Aplysia californica, that these peptides could have various effects on the activity of central neurones (reviewed by Mayeri and Rothman, 1985) led to the hypothesis that egg-laying behaviour is a neuroendocrine fixed action pattern controlled and coordinated by the concerted actions of the released peptides (Scheller and Axel, 1984). This hypothesis is also thought to apply to Lymnaea stagnalis (Vreugdenhil et al. 1988) because of the structural similarities between precursors of Aplysia californica and Lymnaea stagnalis egg-laying hormones. In this paper we investigate how the sequence of the various components of the egg-laying behaviour pattern is achieved.


Author(s):  
M. Wilbrink ◽  
R. Zul ◽  
E.W. Roubos ◽  
A. ter Maat ◽  
T.A. de Vlieger ◽  
...  

1989 ◽  
Vol 164 (5) ◽  
pp. 673-683 ◽  
Author(s):  
Andries Ter Maat ◽  
Anton W. Pieneman ◽  
Jan Tijmen Goldschmeding ◽  
Willem F. E. Smelik ◽  
Graham P. Ferguson

1989 ◽  
Vol 37 (1) ◽  
pp. 7-14 ◽  
Author(s):  
R W Dirks ◽  
A K Raap ◽  
J Van Minnen ◽  
E Vreugdenhil ◽  
A B Smit ◽  
...  

To develop and optimize non-radioactive in situ hybridization techniques for mRNA detection, we used the neuropeptidergic system of the pond snail Lymnaea stagnalis as a biological model system. First, we investigated the in situ hybridization procedure using radioactive-labeled cDNA and synthetic oligonucleotide probes specific for egg-laying hormone (ELH) mRNA and molluscan insulin-like peptide (MIP) mRNA. The results show an intense grain deposit above the caudodorsal cells and light-green cells expressing, respectively, ELH mRNA and MIP mRNA. Good results with relation to signal strength and tissue morphology were obtained with freeze-dry paraformaldehyde vapor fixation. The necessity to perform tissue pre-treatment appeared to be dependent on the cell type of interest. The optimized in situ hybridization protocol proved to be applicable using probes that are either sulfonated/transaminated or labeled with acetylaminofluorene (AAF). In situ hybridization of such haptenized probes led to intense and specific staining of the cytoplasm of the caudodorsal cells. Egg-laying hormone mRNA appeared not to be homogeneously distributed in the cytoplasm but showed a "patch-like" pattern. Nuclear and axoplasmic staining for mRNA was also observed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
István Fodor ◽  
Réka Svigruha ◽  
Zsolt Bozsó ◽  
Gábor K. Tóth ◽  
Tomohiro Osugi ◽  
...  

AbstractIn vertebrates, gonadotropin-releasing hormone (GnRH) peptide is the central mediator of reproduction. Homologous peptides have previously also been identified in molluscan species. However, emerging evidence suggests that these molecules might serve diverse regulatory functions and proposes to consider them as corazonin (CRZ). We previously isolated the full-length cDNA of the invGnRH/CRZ peptide (termed ly-GnRH/CRZ) in the well-established invertebrate model species, the great pond snail Lymnaea stagnalis; however, its predicted functions remain to be verified. In this study, we first confirmed the presence of the deduced active peptide from the central nervous system of L. stagnalis. Further, we performed in vivo and in vitro studies to explore the functions of ly-GnRH/CRZ. Injection of sexually mature specimens with synthetic active peptide had an inhibitory effect on locomotion and an acceleratory effect on egg-laying, but had no effect on feeding. The previously predicted modulatory effect of ly-GnRH/CRZ was supported by its identified co-localization with serotonin on the surface of the heart atria. Lastly, we demonstrated not only the presence of ly-GnRH/CRZ in the penial complex but also that ly-GnRH/CRZ-containing neurons project to the efferent penis nerve, suggesting ly-GnRH/CRZ may directly modulate the motor output of this peripheral tissue. Overall, our findings strongly support that ly-GnRH/CRZ is a multifunctional neuropeptide. These results contribute to the understanding of the GnRH superfamily and, more broadly, disciplines such as comparative endocrinology and neurobiology.


1994 ◽  
Vol 197 (1) ◽  
pp. 79-99
Author(s):  
P Hermann ◽  
A Maat ◽  
R Jansen

Behavioural and neurophysiological techniques were used to study the neuronal control of shell turning during egg-laying in the pond snail Lymnaea stagnalis. Egg-laying consists of three phases: resting, turning and oviposition, and is triggered by an electrical discharge in a group of neuroendocrine cells, the caudodorsal cells. During the discharge, several peptides encoded on two CDCH genes are known to be released. Behavioural experiments in which different combinations of nerves were lesioned indicated that the inferior cervical nerves are necessary for turning behaviour to occur. The right inferior cervical nerve innervates the right dorsal longitudinal muscle and contains axons of neurones that are active just prior to, and during, shell movements in freely behaving animals. These axons are probably the axons of motor neurones. The motor neurones of the dorsal longitudinal muscle were identified in the cerebral A and pedal N clusters. We have demonstrated that there is a correlation between the state of excitability of the caudodorsal cells and the electrical activity of the pedal N motor neurones. Our results indicate that the pedal N motor neurones are involved in executing the turning phase during egg-laying.


1997 ◽  
Vol 78 (6) ◽  
pp. 2859-2869 ◽  
Author(s):  
Petra M. Hermann ◽  
Robert P. J. de Lange ◽  
Anton W. Pieneman ◽  
Andries ter Maat ◽  
Rene F. Jansen

Hermann, Petra M., Robert P. J. de Lange, Anton W. Pieneman, Andries ter Maat, and Rene F. Jansen. Role of neuropeptides encoded on CDCH-1 gene in the organization of egg-laying behavior in the pond snail, Lymnaea stagnalis. J. Neurophysiol. 78: 2859–2869, 1997. Egg laying in the pond snail Lymnaea stagnalis is triggered by a discharge of the neuroendocrine caudodorsal cells (CDCs). The CDCs expresses three different caudorsal cell hormone (CDCH) genes. This gene family expresses, in total, 11 different peptides among which is the ovulation hormone. Besides the CDCs, the CDCH gene family is expressed in other central and peripheral neurons. In this study, we investigated the roles the different CDCH peptides play in the organization of egg-laying behavior. Egg-laying behavior is a sequence of stereotyped movements in which three phases can be distinguished: resting, turning, and oviposition. We have used the excitation of right pedal N (RPeN) motor neurons as a simple analogue of shell-turning behavior, one of the elements of egg-laying behavior. RPeN motor neurons were inhibited during the resting phase of egg laying but were subsequently excited at the onset of and during the turning phase. The excitatory effect could be evoked by application of beta3-CDCP on RPeN motor neurons in the CNS as well as in isolation but not by the ovulation hormone, alpha-CDCP or Calfluxin, the other CDCH-1 peptides tested. The ovulation hormone itself caused inhibition of RPeN motor neurons. Anti-CDCH–1 positive fiber tracts were found close to the cell bodies and axons of the RPeN motor neurons. Electrical stimulation of a nerve that contains these fibers resulted in excitation of the RPeN motor neurons. The effects of injection of CDCH-1 peptides into intact animals correlated well with the effects of these peptides on RPeN motor neurons. Injection of beta3-CDCP or alpha-CDCP into intact animals resulted in immediate turning behavior in the absence of egg laying itself. The ovulation hormone and Calfluxin had no immediate effect on the behavior. Furthermore, our data indicate that the individual CDCH-1 peptides act on different targets.


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