Tmod2 Is a Regulator of Cocaine Responses through Control of Striatal and Cortical Excitability and Drug-Induced Plasticity
Document Type
Article
Publication Date
5-1-2024
Original Citation
Mitra A,
Deats S,
Dickson PE,
Zhu J,
Gardin J,
Nieman B,
Henkelman R,
Tsai N,
Chesler E,
Zhang Z,
Kumar V.
Tmod2 Is a Regulator of Cocaine Responses through Control of Striatal and Cortical Excitability and Drug-Induced Plasticity J Neurosci. 2024;44(18):e1389232024.
Keywords
JMG, SS1, Animals, Cocaine, Neuronal Plasticity, Mice, Mice, Knockout, Male, Corpus Striatum, Mice, Inbred C57BL, Cerebral Cortex, Female, Cocaine-Related Disorders, Microfilament Proteins, Cortical Excitability, Dopamine Uptake Inhibitors
JAX Source
J Neurosci. 2024;44(18):e1389232024.
ISSN
1529-2401
PMID
38508714
DOI
https://doi.org/10.1523/JNEUROSCI.1389-23.2024
Grant
This work was supported by the National Institute on Drug Abuse (NIDA) grant the National Institutes of Health NIDA U01DA041668, U01DA051235, and R33DA050837 and the Brain and Behavioral Foundation Young Investigator Award to V.K. and 5P50DA039841 to E.J.C
Abstract
Drugs of abuse induce neuroadaptations, including synaptic plasticity, that are critical for transition to addiction, and genes and pathways that regulate these neuroadaptations are potential therapeutic targets. Tropomodulin 2 (Tmod2) is an actin-regulating gene that plays an important role in synapse maturation and dendritic arborization and has been implicated in substance abuse and intellectual disability in humans. Here, we mine the KOMP2 data and find that Tmod2 knock-out mice show emotionality phenotypes that are predictive of addiction vulnerability. Detailed addiction phenotyping shows that Tmod2 deletion does not affect the acute locomotor response to cocaine administration. However, sensitized locomotor responses are highly attenuated in these knock-outs, indicating perturbed drug-induced plasticity. In addition, Tmod2 mutant animals do not self-administer cocaine indi- cating lack of hedonic responses to cocaine. Whole-brain MR imaging shows differences in brain volume across multiple regions, although transcriptomic experiments did not reveal perturbations in gene coexpression networks. Detailed electrophysiological characterization of Tmod2 KO neurons showed increased spontaneous firing rate of early postnatal and adult cortical and striatal neurons. Cocaine-induced synaptic plasticity that is critical for sensitization is either missing or reciprocal in Tmod2 KO nucleus accumbens shell medium spiny neurons, providing a mechanistic explanation of the cocaine response phenotypes. Combined, these data, collected from both males and females, provide compelling evidence that Tmod2 is a major regulator of plasticity in the mesolimbic system and regulates the reinforcing and addictive properties of cocaine.