Andrew Holmes

Astrocytes gate the recall of emotional fear memory

Abstract

Brain systems mediating behavioral responses to previously encountered threats are critical to animals’ survival. The basolateral amygdala (BLA) mediates the expression of fear memory, but the contribution of BLA astrocytes to fear remains unclear. Employing in vivo calcium imaging, we found that BLA astrocytes dynamically track behavioral fear state and, using chronic and acute calcium manipulations, causally and bidirectionally link astrocyte-calcium levels with fear expression. In vivo cellular-resolution calcium imaging revealed how neuronal representations of fear are shaped by astrocytes. Our findings reveal that retrieval of fear memory involves a previously unknown degree of functional interaction between BA astrocytes and neurons, redefining current neurocircuit models of an essential survival function.

Biography

Andrew Holmes specializing in neuroscience, with a focus on behavior and addiction. He was trained in the UK, where received his Bachelor’s (Hons) degree in Psychology and his Doctorate in Behavioral Pharmacology. He received postdoctoral training in behavioral neuroscience and behavioral genetics from Dr. Jacki Crawley at the NIMH. He was recruited to the NIAAA in 2004 and is Currently leading the Laboratory of Behavioral and Genomic Neuroscience at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH), where he studies brain regulation of emotion and cognition using animal models.

He obtained numerous awards, including in 2022 the NIAAA Scientific Achievement Award for ‘scientists who have made an outstanding contribution to scientific research.’.

Research Topics

The mission of the Laboratory of Behavioral and Genomic Neuroscience is to contribute to a deeper understanding of the causes of alcoholism and comorbid neuropsychiatric conditions such as mood and anxiety disorders. Our goal is to help identify new directions for the prevention and effective treatment of these devastating diseases. To this end, we are using models of chronic alcohol exposure and chronic stress to examine how these environmental insults reshape brain circuits to modify behavior, and why they do so in a manner that varies greatly from individual to individual as a function of genetics, sex and age. A major current focus of our work is how alcohol and stress affect the structure and function of circuits interconnecting the prefrontal cortex with limbic and dorsal striatal regions that are critical for the regulation of emotion, cognition and executive control over drug-seeking.