Abstract
Tics and compulsions in comorbid Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD) are associated with chronic hyperactivity of parallel cortico/amygdalo-striato-thalamo-cortical (CSTC) loop circuits. Comorbid TS- & OCD-like behaviors have likewise been observed in D1CT-7 mice, in which an artificial neuropotentiating transgene encoding the cAMP-elevating intracellular subunit of cholera toxin (CT) is chronically expressed selectively in somatosensory cortical & amygdalar dopamine (DA) D1 receptor-expressing neurons that activate cortico/amygdalo-striatal glutamate (GLU) output. We've now examined in D1CT-7 mice whether the chronic GLU output from their potentiated cortical/limbic CSTC subcircuit afferents associated with TS- & OCD-like behaviors elicits desensitizing neurochemical changes in the striatum (STR). Microdialysis-capillary electrophoresis and in situ hybridization reveal that the mice's chronic GLU-excited STR exhibits pharmacodynamic changes in three independently GLU-regulated measures of output neuron activation, co-excitation, and desensitization, signifying hyperactive striatal CSTC output and compensatory striatal glial and neuronal desensitization: 1) Striatal GABA, an output neurotransmitter induced by afferent GLU, is increased. 2) Striatal D-serine, a glial excitatory co-transmitter inhibited by afferent GLU, is decreased. 3) Striatal Period1 (Per1), which plays a non-circadian role in the STR as a GLU + DA D1- (cAMP-) dependent repressor thought to feedback-inhibit GLU + DA- triggered ultradian urges and motions, is transcriptionally abolished. These data imply that chronic cortical/limbic GLU excitation of the STR desensitizes its co-excitatory D-serine & DA inputs while freezing its GABA output in an active state to mediate chronic tics and compulsions − possibly in part by abolishing striatal Per1-dependent ultradian extinction of urges and motions.
Original language | English (US) |
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Pages (from-to) | 11-20 |
Number of pages | 10 |
Journal | Journal of Chemical Neuroanatomy |
Volume | 89 |
DOIs | |
State | Published - Apr 2018 |
Bibliographical note
Funding Information:The authors thank Dr. Mary E. Harrington (Smith College) for helpful advisory supervision and training assistance to AZS. This work was supported by the National Institutes of Health [grant numbers NS043304 to MTB, R03MH53553 to FHB, R21NS045566 to FHB]; the National Alliance for Research on Schizophrenia and Depression , the National Alliance for the Mentally Ill , and the Rochester Area Alliance for the Mentally Ill [Jeff Sutton Memorial NARSAD-NAMI-RAAMI Young Investigator Award to FHB]; and research grants from the Tourette Syndrome Association [FHB] and the University of Minnesota Foundation [Orphan Therapeutic Fund to FHB].
Funding Information:
The authors thank Dr. Mary E. Harrington (Smith College) for helpful advisory supervision and training assistance to AZS. This work was supported by the National Institutes of Health [grant numbers NS043304 to MTB, R03MH53553 to FHB, R21NS045566 to FHB]; the National Alliance for Research on Schizophrenia and Depression, the National Alliance for the Mentally Ill, and the Rochester Area Alliance for the Mentally Ill [Jeff Sutton Memorial NARSAD-NAMI-RAAMI Young Investigator Award to FHB]; and research grants from the Tourette Syndrome Association [FHB] and the University of Minnesota Foundation [Orphan Therapeutic Fund to FHB].
Publisher Copyright:
© 2018 The Authors
Keywords
- Compulsion
- D-serine
- Glutamate
- Per1
- Tourette
- Transgenic