TY - JOUR
T1 - Chronic amphetamine treatment enhances corticotropin-releasing factor-induced serotonin release in the amygdala
AU - Scholl, Jamie L.
AU - Vuong, Shawn M.
AU - Forster, Gina L.
N1 - Funding Information:
This work was supported by grants NIH R01 DA019921 and NIH P20 RR015567 which is a designated Center of Biomedical Research Excellence (COBRE). S.V. was supported by a University of South Dakota Undergraduate Research Award . We thank Dr. Kenneth Renner and Jeffrey Barr for valuable technical assistance and advice regarding these experiments.
PY - 2010/10
Y1 - 2010/10
N2 - Amphetamine use is associated with dysphoric states, including heightened anxiety, that emerge within 24. h of withdrawal from the drug. Corticotropin-releasing factor increases serotonin release in the central nucleus of the amygdala, and this neurochemical circuitry may play a role in mediating fear and anxiety states. We have previously shown that chronic amphetamine treatment increases corticotropin-releasing factor receptor type-2 levels in the serotonergic dorsal raphe nucleus of the rat. Therefore, we hypothesized that chronic amphetamine treatment would enhance the amygdalar serotonergic response to corticotropin-releasing factor infused into the dorsal raphe nucleus. Male rats were injected once-daily with d-amphetamine (2.5. mg/kg i.p., or saline) for two weeks. Serotonin release within the central nucleus of the amygdala in response to intra-raphe infusion of corticotropin-releasing factor (100. ng) was measured 24. h after the last treatment in urethane-anesthetized (1.8. mg/kg, i.p.) rats using in vivo microdialysis. Rats pretreated with amphetamine showed significantly enhanced serotonin release in the central nucleus of the amygdala in response to corticotropin-releasing factor infusion when compared to saline pretreated rats. Furthermore, this enhanced response was blocked by the corticotropin-releasing factor type-2 receptor antagonist antisauvagine-30 (2μg) infused into the dorsal raphe nucleus. These results suggest increased sensitivity to corticotropin-releasing factor as mediated by type-2 receptors following chronic amphetamine treatment, which may underlie dysphoric states observed during amphetamine withdrawal.
AB - Amphetamine use is associated with dysphoric states, including heightened anxiety, that emerge within 24. h of withdrawal from the drug. Corticotropin-releasing factor increases serotonin release in the central nucleus of the amygdala, and this neurochemical circuitry may play a role in mediating fear and anxiety states. We have previously shown that chronic amphetamine treatment increases corticotropin-releasing factor receptor type-2 levels in the serotonergic dorsal raphe nucleus of the rat. Therefore, we hypothesized that chronic amphetamine treatment would enhance the amygdalar serotonergic response to corticotropin-releasing factor infused into the dorsal raphe nucleus. Male rats were injected once-daily with d-amphetamine (2.5. mg/kg i.p., or saline) for two weeks. Serotonin release within the central nucleus of the amygdala in response to intra-raphe infusion of corticotropin-releasing factor (100. ng) was measured 24. h after the last treatment in urethane-anesthetized (1.8. mg/kg, i.p.) rats using in vivo microdialysis. Rats pretreated with amphetamine showed significantly enhanced serotonin release in the central nucleus of the amygdala in response to corticotropin-releasing factor infusion when compared to saline pretreated rats. Furthermore, this enhanced response was blocked by the corticotropin-releasing factor type-2 receptor antagonist antisauvagine-30 (2μg) infused into the dorsal raphe nucleus. These results suggest increased sensitivity to corticotropin-releasing factor as mediated by type-2 receptors following chronic amphetamine treatment, which may underlie dysphoric states observed during amphetamine withdrawal.
KW - (Rat)
KW - CRF receptor
KW - Central nucleus of the amygdala
KW - Dorsal raphe nucleus
KW - Microdialysis
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U2 - 10.1016/j.ejphar.2010.07.008
DO - 10.1016/j.ejphar.2010.07.008
M3 - Article
C2 - 20655906
AN - SCOPUS:77955773086
VL - 644
SP - 80
EP - 87
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
SN - 0014-2999
IS - 1-3
ER -