Heterogeneity in the ventral tegmental area, does the structural diversity of this region influence the function of midbrain glutamatergic circuits?

  • Amber Tear

Student thesis: Master's Thesis

Abstract

From its location in the ventral midbrain, the ventral tegmental area (VTA) is involved in a wide and varying array of functions, ranging from the processing of and responding to rewarding stimuli, the modulation of mood-related behaviour, and the co-ordination of locomotor activity. A region composed of glutamatergic, GABAergic and dopaminergic cell types, the VTA features ananatomical and functional heterogeneity that has not been fully explored. The ensuing experiment investigates the role of glutamatergic neurons; the least understood neurochemical subtype in the VTA, in the production of reward related and locomotor activity. Therefore, the aim of the present study was to explore the role of glutamate in the production of reward-related and locomotor behaviour, thereby promoting a greater understanding of VTA physiology and the functional contributions of VTA afferents. A glutamate reuptake inhibitor, DL-TBOA, was applied to two different regions of the VTA; the anterior and posterior VTA, to assess the differential involvement of this neurotransmitter in behaviour produced by either region. Microinjection of the glutamate reuptake inhibitor elicited significant changes in locomotor activity that were sustained over the testing period, with a significant decrease when injected into the pVTA and selective increases in activity when injected into the aVTA. No alterations were observed in reward-related activity. These results suggest evidence for a functional and structural distinction between glutamate networks in the anterior and posterior VTA.
Date of Award11 Aug 2016
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorPhilip Winn (Supervisor) & Morag Farquhar (Supervisor)

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