Marco Bocchio wins the Gotch Memorial Prize 2013 for the best DPhil Transfer Status report of an Oxford graduate student in the field of Physiology. The award is £1,000.
The title of his transfer report is "Serotonergic neuromodulation of the mouse amygdala".
Recent studies in animals and humans have proven that serotonergic neurotransmission in the Basolateral Amygdala (BLA) is a critical component for the regulation of emotional behaviour and psychiatric disorders. However, the effects of serotonergic transmission on BLA neuronal network are currently poorly understood.
The report investigates the effect of serotonin (5-Hydroxytriptamine, 5-HT) on:
1) GABAergic interneurons (INs) innervating Principal Neurons (PNs) of the Basal Amygdala in mice overexpressing the serotonin transporter (5-HTT OE), an animal model displaying reduced anxiety; and 2) neurons of the Lateral Amygdala (LA) expressing neuronal nitric oxide synthase (nNOS), a cell type displaying Low-threshold Spiking (LTS) features.
The experiments described hereby show that overexpression of 5-HTT leads to a deficit in GABAergic INs activation in the Basal Amygdala (BA), namely reduced inhibition onto PN.
Additionally, 5-HT elicits a switch from tonic firing to burst firing of nNOS+ neurons of the LA, potentially driven by hyperpolarization. This contrasts with the known depolarizing action of 5-HT on other GABAergic populations investigated so far. The description of the anatomical aspects and electrophysiological responses of nNOS+ neurons is also addressed. Results suggest that this cell population is likely to be formed by long-range GABAergic projection neurons, the presence of which has never been reported in the BLA.