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Neural substrates underlying fear-evoked freezing: the periaqueductal grey – cerebellar link

Koutsikou, Stella, Crook, J.J., Earl, E.V., Leith, J.L., Watson, T.C., Lumb, B.M., Apps, R. (2014) Neural substrates underlying fear-evoked freezing: the periaqueductal grey – cerebellar link. The Journal of Physiology, 592 (10). pp. 2197-2213. ISSN 0022-3751. E-ISSN 1469-7793. (doi:10.1113/jphysiol.2013.268714) (KAR id:63364)


The central neural pathways involved in fear-evoked behaviour are highly conserved across mammalian species, and there is a consensus that understanding them is a fundamental step towards developing effective treatments for emotional disorders in man. The ventrolateral periaqueductal grey (vlPAG) has a well-established role in fear-evoked freezing behaviour. The neural pathways underlying autonomic and sensory consequences of vlPAG activation in fearful situations are well understood, but much less is known about the pathways that link vlPAG activity to distinct fear- evoked motor patterns essential for survival. In adult rats, we have identified a pathway linking the vlPAG to cerebellar cortex, which terminates as climbing fibres in lateral vermal lobule VIII (pyramis). Lesion of pyramis input-output pathways disrupted innate and fear-conditioned freezing behaviour. The disruption in freezing behaviour was strongly correlated to the reduction in the vlPAG-induced facilitation of -motoneurone excitability observed after lesions of the pyramis. The increased excitability of -motoneurones during vlPAG activation may therefore drive theincreaseinmuscletonethatunderliesexpressionoffreezingbehaviour.

Item Type: Article
DOI/Identification number: 10.1113/jphysiol.2013.268714
Uncontrolled keywords: Periaqueductal grey, cerebellar vermis, fear
Subjects: Q Science > QP Physiology (Living systems)
Divisions: Divisions > Division of Natural Sciences > Medway School of Pharmacy
Depositing User: Stella Koutsikou
Date Deposited: 12 Sep 2017 13:58 UTC
Last Modified: 04 Jul 2023 11:26 UTC
Resource URI: (The current URI for this page, for reference purposes)

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