MSc Exit Seminar – Nariman Hossein-Javaheri (Buck Lab)

MSc Exit Seminar

Wednesday September 28^th, 12:30 pm – Ramsay Wright Building, Rm. 432

Nariman Hossein-Javaheri (Buck lab)

“Goldfish Pyramidal and Stellate Neurons Respond Differently to Anoxia“

Abstract

With oxygen deprivation the mammalian brain undergoes excito-toxic cell death but this does not occur in the anoxia tolerant goldfish. Since GABA is the major inhibitory neurotransmitter in the brain, I investigated its potential role in preventing hyper-excitability in goldfish telencephalon neurons. Utilizing patch-clamp technique, the electrical activities of both excitatory (pyramidal) and inhibitory (stellate) neurons were recorded. With anoxia, membrane potential depolarized in both cell types. While pyramidal cells remained mostly quiescent, action-potential frequency of the stellate neurons increased. Further, the GABA_A receptor reversal potential (E­_GABA) was depolarizing in both cell types. Inhibition of GABA_A receptors reversed the anoxic response, while GABA_B receptor inhibition did not induce a response. Co-antagonism of both GABA_A/B receptors generated seizure-like neuronal activity. I conclude that GABA is vital for the anoxic survival of the goldfish and that the increased stellate neuron activity likely results in inhibition of pyramidal neuron activity with anoxia.

Ramsay Wright is a wheelchair accessible building.