Photoperiod dependent plasticity of GABA-mediated effects on neuronal activity in the pond snail Lymnaea stagnalis
نویسنده
چکیده
GABA is the primary inhibitory neurotransmitter in the mature mammalian CNS. Within the snail central ganglion, however, there are contradictory reports on the role of GABA, citing both inhibitory and excitatory effects. Previous work has suggested a seasonal shift in the polarity induced by GABA. My thesis work investigated whether changes in photoperiod were responsible for the seasonal shift in GABAergic polarity. Using intracellular sharp recordings from cluster F neurons within the pedal ganglia, I determined that the majority of snails exposed to either a 16h:8h or 8h:16h light:dark cycle exhibited significant hyperpolarizing inhibitory responses or depolarizing excitatory responses to GABA application, respectively. Additionally, using gramicidin-perforated patch recordings I found a shift in the reversal potential for GABA. I conclude that the seasonal shift in GABA-mediated effects results from a shift in intracellular [Cl ̄] that is photoperiod dependent and is likely mediated through the relative efficacy of cation chloride co-transporters.
منابع مشابه
In vitro effects of fipronil on neuronal excitability in mammalian and molluscan nervous systems.
The effect of the insecticide fipronil on non-target organisms was studied on rat brain slices and identified giant neurons of the pond snail Lymnaea stagnalis. This compound acts as an antagonist on GABA(A) receptors. Although fipronil has moderate mammalian toxicity, our experiments confirmed that it modifies neuronal excitability in the rat somatosensory cortex. The amplitudes of evoked fiel...
متن کاملExcitatory actions of GABA mediate severe-hypoxia-induced depression of neuronal activity in the pond snail (Lymnaea stagnalis).
To characterize the effect of severe hypoxia on neuronal activity, long-term intracellular recordings were made from neurones in the isolated central ring ganglia of Lymnaea stagnalis. When a neurone at rest in normoxia was subjected to severe hypoxia, action potential firing frequency decreased by 38% (from 2.4-1.5 spikes s(-1)), and the resting membrane potential hyperpolarized from -70.3 to ...
متن کاملAdenosinergic modulation of neuronal activity in the pond snail Lymnaea stagnalis.
Adenosine has been termed a retaliatory metabolite and its neuroprotective effects have been implicated in the hypoxia tolerance of several species; however, its role in the invertebrate CNS remains unclear. To determine if adenosine modulates neuronal activity in invertebrate neurons, we conducted whole-cell recordings from neurons in the central ring ganglia of the anoxia-tolerant pond snail ...
متن کاملShort Communication Neuronal Feedback in Egg-laying Behaviour of the Pond Snail Lymnaea Stagnalis
متن کامل
Structure‐dependent effects of amyloid‐β on long‐term memory in Lymnaea stagnalis
Amyloid-β (Aβ) peptides are implicated in the causation of memory loss, neuronal impairment, and neurodegeneration in Alzheimer's disease. Our recent work revealed that Aβ 1-42 and Aβ 25-35 inhibit long-term memory (LTM) recall in Lymnaea stagnalis (pond snail) in the absence of cell death. Here, we report the characterization of the active species prepared under different conditions, describe ...
متن کامل