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Shank, A.

Publications and source records attributed to Shank, A..

2 recordsLinked to original sources

Local control of dopamine release in nucleus accumbens gates opioid withdrawal aversion

The opioid crisis has emphasized the need for more effective treatments for opioid use disorder (OUD)1-3, which is characterized by habitual opioid use to avoid withdrawal symptoms4,5. Both physical and affective symptoms contribute to opioid withdrawal yet whether different neural mechanisms mediate these different symptom domains and contribute distinctly to opioid relapse is unknown. While neurons expressing mu opioid receptors (MORs) gate opioids reinforcing effects6-8 by increasing dopamine (DA) release in nucleus accumbens (NAc), sharp decreases in NAc DA release are associated with withdrawal9-11, the cellular and circuit mechanisms of which are unknown. Here we describe an unusual population of evolutionarily-conserved MOR+ neurons in the NAc expressing the transcription factor Tshz1. Increased activity in these neurons is required for withdrawal aversion learning. Deletion of MORs in Tshz1 neurons prevented withdrawal-induced decreases in DA release and affective aversion, but not physical symptoms associated with withdrawal. Pharmacological activation of mGluR8, which is preferentially expressed in Tshz1 neurons, reduced withdrawal aversion. Thus, by dissociating the circuit mechanisms contributing to the physical and affective components of opioid withdrawal focusing on the critical role of Tshz1 neurons, we have identified a novel druggable target with therapeutic potential for treating key OUD withdrawal symptoms.

neuroscience↗

Parallel processing of sensory cue and spatial information in the Dentate Gyrus

During exploration, animals form an internal map of an environment by combining information about specific sensory cues or landmarks with the animals motion through space, a process which critically depends on the mammalian hippocampus. The dentate gyrus (DG) is the first stage of the hippocampal trisynaptic circuit where self-motion and sensory cue information are integrated, yet it remains unknown how neurons within the DG encode both cue related ("what") and spatial ("where") information during cognitive map formation. Using two photon calcium imaging in head fixed mice running on a treadmill, along with on-line sensory cue manipulation at specific track locations, we have identified robust sensory cue responses in DG granule cells largely independent of spatial location. Granule cell cue responses are stable for long periods of time, selective for the modality of the stimulus and accompanied by strong inhibition of the firing of other active neurons. At the same time, there is a smaller fraction of neurons whose firing is spatially tuned but insensitive to the presentation of nearby cues, similar to traditional place cells. These results demonstrate the existence of "cue cells" in addition to the better characterized "place cells" in the DG, an important heterogeneity that has been previously overlooked. We hypothesize that the granule cell population may support multiple channels of spatial and non-spatial information that contribute distinctly to local and down-stream computations and impact the role of the dentate gyrus in spatial navigation and episodic memory.

neuroscience↗