Dopaminergic control of astrocytic calcium dynamics in situ and its potential effect on local synaptic activity

• Main Author: Jennings, A. E.
• Published: University College London (University of London) 2014
• Subjects: 616.85
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.632074

Astrocytes in culture display large cytosolic calcium increases upon stimulation with dopamine, however the mechanism and physiological significance of this calcium response is still unknown. In this thesis, I demonstrate that hippocampal astrocytes in situ respond to dopamine with similar large calcium transients. I also describe a novel astrocyte calcium decrease, which appears specific to dopaminergic stimulation. Dopamine is a potent neuromodulator of hippocampal synaptic activity, as are astrocytes. However, I found no evidence to suggest that dopamine-induced calcium transients in astrocytes affect excitatory synaptic transmission and its short-term plasticity in the hippocampal stratum radiatum. In perforant path - CA1 pyramidal synapses of stratum lacunosum-moleculare, astrocytes were found to lessen the inhibitory effect of dopamine on evoked PTP. This work shows for the first time that astrocytes in situ can robustly respond to dopamine with a complex Ca2+ signal thus may participate in dopaminergic signalling in the brain.