Prepulse inhibition of the acoustic startle reflex impairment by 5-HT2A receptor activation in the inferior colliculus is prevented by GABAA receptor blockade in the pedunculopontine tegmental nucleus.
Behavioural brain research June 25, 2023 Rodolpho Pereira de Oliveira, Thais Yokoyama, Lucas de Santana Cardoso Thomaz et al. 2 citations
Activation of 5-HT2A receptors in the inferior colliculus (IC) by the agonist DOI reduces prepulse inhibition (PPI) of the acoustic startle in male Wistar rats, mimicking a schizophrenia-like deficit. A neural pathway connecting the IC and the pedunculopontine tegmental nucleus (PPTg) was identified. DOI injection decreased c-Fos-labeled cells in both the IC and PPTg, suggesting increased GABA activity. Blocking GABAA receptors in the PPTg with bicuculline prevented the PPI deficit caused by DOI in the IC. These findings indicate that IC 5-HT2A receptors help regulate inhibitory pathways mediating PPI, involving GABAergic transmission in the IC-PPTg circuit.