Cerebellar control of fear learning via the cerebellar nuclei–Multiple pathways, multiple mechanisms?

Abstract

Fear learning is mediated by a large network of brain structures and the understanding of their roles and interactions is constantly progressing. There is a multitude of anatomical and behavioral evidence on the interconnection of the cerebellar nuclei to other structures in the fear network. Regarding the cerebellar nuclei, we focus on the coupling of the cerebellar fastigial nucleus to the fear network and the relation of the cerebellar dentate nucleus to the ventral tegmental area. Many of the fear network structures that receive direct projections from the cerebellar nuclei are playing a role in fear expression or in fear learning and fear extinction learning. We propose that the cerebellum, via its projections to the limbic system, acts as a modulator of fear learning and extinction learning, using prediction-error signaling and regulation of fear related thalamo-cortical oscillations.

Selection for Reduced Fear of Humans Changes Brain and Cerebellum Size in Red Junglefowl in Line with Effects of Chicken Domestication

“…Hence, the cerebellum is a key aspect of the brain's "fear network", together with the amygdala, prefrontal cortex, and hippocampus. The cerebellar nuclei are connected to these other brain parts and essential to this fear network [40]. The fastigial nucleus is a part of the cerebellum that projects to the thalamus, a brain region involved in emotion regulation.…”

Absence of modulatory effects of 6Hz cerebellar transcranial alternating current stimulation on fear learning in men

“…It is possible that these processes involve neural mechanisms better aligned with frequencies outside of 6 Hz. For instance, as suggested by Urrutia Desmaison et al (2023) , the cerebellum appears to regulate 4 Hz oscillations between the cortex and thalamus during the retrieval of fear memories, potentially affecting the fear extinction process. Additionally, in the context of cerebello-hippocampal interaction the synchronization of Purkinje cell activity in both Crus I and Lobulus Simplex with the medial prefrontal cortex and hippocampal CA1 occurs in the delta (0.5–4 Hz) and, for Lobulus simplex, also in the gamma oscillation range (25–100 Hz) ( McAfee et al, 2019 ).…”