DOPAMINERGIC MODULATION OF ASTROCYTES IN THE ANTERIOR CINGULATE CORTEX GATES INNATE FEAR INDUCED AVOIDANCE LEARNING

Innate‑fear‑driven learning is an ethologically vital mechanism that enables prey animals to recognize and avoid dangerous environments. Although key pathways for innate‑fear processing in the limbic system have become increasingly known, the precise cellular sites and mechanisms by which these stimuli are converted into long‑term avoidance memories remain unclear. The anterior cingulate cortex (ACC) is a central hub for emotional processing and is innervated by dopaminergic projections signaling aversive states from the ventral tegmental area (VTA).
We hypothesize that dopaminergic modulation in the ACC gates synaptic plasticity, thereby transforming innate‑fear cues into avoidance memories.
We employ a novel one‑day conditioned‑place avoidance paradigm using the predator odor trimethylthiazoline (TMT) to study ACC function in aversive memory formation. We demonstrate that both the ACC and dopaminergic inputs from the VTA are required for conditioned avoidance learning. At the network and cellular levels, dopaminergic activation of astrocytes in the ACC emerges as a critical “gate” for learning: astrocyte‑mediated calcium signaling promotes the induction of spike‑timing–dependent long‑term potentiation (tLTP) at afferent synapses onto layer 5 pyramidal neurons. Selective blockade of astrocytic calcium transients abolishes both tLTP and conditioned avoidance behavior.
By placing astrocytes at the intersection of neuromodulatory and glutamatergic pathways, our results uncover a glial “checkpoint” essential for synaptic potentiation and innate‑fear learning in the ACC. Targeting this astrocyte‑mediated gate may therefore offer novel strategies to modulate maladaptive fear responses in stress‑related disorders.