Fronto-temporal galanin modulates impulse control

• Published in: Psychopharmacology 2020-02, Vol.237 (2), p.291-303
• Main Authors: Messanvi, F., Perkins, A., du Hoffmann, J., Chudasama, Y.
• Format: Article
• Language: English
• Subjects: Agonists; Animal behavior; Animals; Biomedical and Life Sciences; Biomedicine; Bradykinin - administration & dosage; Bradykinin - analogs & derivatives; Cognitive ability; Conditioning, Operant - drug effects; Conditioning, Operant - physiology; Dose-Response Relationship, Drug; G protein-coupled receptors; Galanin; Galanin - administration & dosage; Galanin - analogs & derivatives; Galanin - physiology; Hippocampus; Hippocampus - drug effects; Hippocampus - physiology; Impulsive behavior; Impulsive Behavior - drug effects; Impulsive Behavior - physiology; Impulsivity; Infusions, Intraventricular; Male; Neuropeptides; Neurosciences; Original Investigation; Peptide Fragments - administration & dosage; Pharmacology/Toxicology; Photic Stimulation - methods; Prefrontal cortex; Prefrontal Cortex - drug effects; Prefrontal Cortex - physiology; Psychiatry; Rats; Rats, Long-Evans; Reaction Time - drug effects; Reaction Time - physiology; Reaction time task; Receptor, Galanin, Type 1 - agonists; Receptor, Galanin, Type 1 - physiology; Temporal cortex
• ISSN: 0033-3158; 1432-2072
• DOI: 10.1007/s00213-019-05365-2

Rationale The neuropeptide galanin has been implicated in a wide range of pathological conditions in which frontal and temporal structures are compromised. It works through three subtypes of G-protein-coupled receptors. One of these, the galanin receptor 1 (Gal-R1) subtype, is densely expressed in the ventral hippocampus (vHC) and ventral prefrontal cortex (vPFC); two brain structures that have similar actions on behavioral control. We hypothesize that Gal-R1 contributes to cognitive-control mechanisms that require hippocampal-prefrontal cortical circuitry. Objective To examine the effect of local vHC and vPFC infusions of M617, a Gal-R1 agonist, on inhibitory mechanisms of response control. Methods Different cohorts of rats were implanted with bilateral guide cannulae targeting the vPFC or the vHC. Following infusion of the Gal-R1 agonist, we examined the animals’ behavior using a touchscreen version of the 5-choice reaction time task (5-choice task). Results The Gal-R1 agonist produced opposing behaviors in the vPFC and vHC, leading to disruption of impulse control when infused in the vPFC but high impulse control when infused into the vHC. This contrast between areas was accentuated when we added variability to the timing of the stimulus, which led to long decision times and reduced accuracy in the vPFC group but a general improvement in performance accuracy in the vHC group. Conclusions These results provide the first evidence of a selective mechanism of Gal-R1–mediated modulation of impulse control in prefrontal-hippocampal circuitry.