Projection from the Amygdala to the Thalamic Reticular Nucleus Amplifies Cortical Sound Responses

• Published in: Cell reports (Cambridge) Vol. 28; no. 3; pp. 605 - 615.e4
• Main Authors: Aizenberg, Mark, Rolón-Martínez, Solymar, Pham, Tuan, Rao, Winnie, Haas, Julie S., Geffen, Maria N.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 16.07.2019; Elsevier
• Subjects: amygdala; Amygdala - cytology; Amygdala - physiology; Animals; auditory cortex; Auditory Cortex - cytology; Auditory Cortex - physiology; Auditory Perception; auditory processing; electrophysiology; Evoked Potentials, Auditory; Female; inhibition; Male; medial geniculate body; Mice; Mice, Inbred C57BL; optogenetics; sensory procession; Thalamic Nuclei - cytology; Thalamic Nuclei - physiology; thalamic reticular nucleus; amygdala; auditory cortex; electrophysiology; optogenetics; thalamic reticular nucleus; medial geniculate body; auditory processing; inhibition; sensory procession
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2019.06.050

Many forms of behavior require selective amplification of neuronal representations of relevant environmental signals. Emotional learning enhances sensory responses in the sensory cortex, yet the underlying circuits remain poorly understood. We identify a pathway between the basolateral amygdala (BLA), an emotional learning center in the mouse brain, and the inhibitory reticular nucleus of the thalamus (TRN). Optogenetic activation of BLA suppressed spontaneous, but not tone-evoked, activity in the auditory cortex (AC), amplifying tone-evoked responses. Viral tracing identified BLA projections terminating at TRN. Optogenetic activation of amygdala-TRN projections further amplified tone-evoked responses in the auditory thalamus and cortex. The results are explained by a computational model of the thalamocortical circuitry, in which activation of TRN by BLA primes thalamocortical neurons to relay relevant sensory input. This circuit mechanism shines a neural spotlight on behaviorally relevant signals and provides a potential target for the treatment of neuropsychological disorders. [Display omitted] •Basolateral amygdala projects to the TRN gating signals to the cortex•BLA-TRN activation amplifies sound responses in the auditory thalamus and cortex•A model for the BLA-TRN-AC connectivity explains the results•This pathway is a potential target for treatment of emotional and sensory disorders Aizenberg et al. show that the projection from the emotional center of the brain, the basolateral amygdala, to the auditory thalamic control area, the thalamic reticular nucleus, gates sensory processing in the cortex.