Central Nervous System Of Lymnaea Stagnalis Research Articles

Src Family Kinases Play a Role in the Functional Clustering of Central Postsynaptic Nicotinic Acetylcholine Receptors

The mechanism of postsynaptic neurotransmitter receptor clustering has been best described at the neuromuscular junction (NMJ), where packets of nicotinic acetylcholine receptors (nAChRs) in muscle fibre are redistributed to the synaptic site upon motor neuron innervation. This process of receptor localisation is facilitated by agrin signalling, and the stability of the resulting nAChR clusters depends upon the activation of Src family kinases (SFKs). In contrast to the NMJ however, the cellular signalling mechanisms orchestrating the clustering of nAChRs in the central nervous system (CNS) remain poorly defined. Furthermore, our understanding of the role of SFKs in the CNS is also limited. Here we provide evidence that SFK activation is required for synapse formation between pairs of identified neurons isolated from the CNS of Lymnaea stagnalis. Furthermore, we suggest that SFKs are involved in the functional redistribution of nAChRs to the synaptic contact sites in isolated axons. To the best of our knowledge, this study is the first to demonstrate a role for SFKs in the clustering of nAChRs in central neurons, suggesting that the mechanisms of receptor clustering between the peripheral and central nervous system are likely conserved.

Alternative splicing generates diversity of VD1/RPD2α peptides in the central nervous system ofLymnaea stagnalis

1. Two giant peptidergic neurons, VD1 and RPD2, of the visceral ganglion and right parietal ganglion of Lymnaea stagnalis, respectively, play an important role in the modulation of complex physiological and behavioral adjustments that occur as a result of changes in O2 availability. 2. By cDNA cloning, we have identified two types of VD1/RPD2 transcripts expressed in VD1 and RPD2. In addition, these transcripts are also expressed in other neurons. 3. Both transcripts encode distinct yet related VD1/RPD2 preprohormones that may be cleaved to yield distinct but overlapping sets of neuropeptides. 4. Using the polymerase chain reaction technique, we could show the existence of additional splice variants. 5. Analysis of the organization of the VD1/RPD2 gene indicates that the alpha peptide coding region is interrupted by a number of introns. 6. We concluded that the mRNA segment encoding the alpha peptide domain of the VD1/RPD2 preprohormones is alternatively spliced, thus generating different alpha peptides.