The Role of Corticotropin-Releasing Factor in Behavioural Responses to Stress

We previously reported the elevation of plasma interleukin (IL)-6 activity in response to immobilization stress in rats. To investigate the role of peripheral corticotropin-releasing factor (CRF) in this response, we examined the effects of CRF antagonists on immobilization-induced IL-6 response. Intravenous pretreatment with either [d-Phe12,Nle21,38,CαMeLeu37]-anti-human rat (h/r) CRF12—41(1.5 mg/kg) or cyclo(30—33)[d-Phe12, Nle21,38,Glu30,Lys33]-h/rCRF12—41(Astressin, 0.5 mg/kg) attenuated the IL-6 response to immobilization, which confirmed our previous finding that systemic administration of an antiserum against CRF blocked this response. In addition, an intraperitoneal injection of h/rCRF (100 μg/kg) or rat urocortin (10 and 100 μg/kg) increased the plasma IL-6 activity, mimicking the response to immobilization. An intravenous injection of h/rCRF (100 μg/kg) also elevated plasma IL-6 in adrenalectomized rats. These findings suggest that peripheral CRF mediates the plasma IL-6 elevation in response to immobilization.

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Temperament, Plasticity, and Emotions in Defensive Behaviour of Paca (Mammalia, Hystricognatha)

Animals ◽

10.3390/ani11020293 ◽

2021 ◽

Vol 11 (2) ◽

pp. 293

Author(s):

Selene S. C. Nogueira ◽

Sérgio L. G. Nogueira-Filho ◽

José M. B. Duarte ◽

Michael Mendl

Keyword(s):

Conservation Status ◽

Behavioural Plasticity ◽

Affective States ◽

Defensive Behaviour ◽

Rapid Adaptation ◽

Behavioural Responses ◽

Judgement Bias ◽

Temperament Dimension ◽

Ambiguous Cue

Within a species, some individuals are better able to cope with threatening environments than others. Paca (Cuniculus paca) appear resilient to over-hunting by humans, which may be related to the behavioural plasticity shown by this species. To investigate this, we submitted captive pacas to temperament tests designed to assess individual responses to short challenges and judgement bias tests (JBT) to evaluate individuals’ affective states. Results indicated across-time and context stability in closely correlated “agitated”, “fearful” and “tense” responses; this temperament dimension was labelled “restless”. Individual “restless” scores predicted responses to novelty, although not to simulated chasing and capture by humans in a separate modified defence test battery (MDTB). Restless animals were more likely to show a greater proportion of positive responses to an ambiguous cue during JBT after the MDTB. Plasticity in defensive behaviour was inferred from changes in behavioural responses and apparently rapid adaptation to challenge in the different phases of the MDTB. The results indicate that both temperament and behavioural plasticity may play a role in influencing paca responses to risky situations. Therefore, our study highlights the importance of understanding the role of individual temperament traits and behavioural plasticity in order to better interpret the animals’ conservation status and vulnerabilities.

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Role of the corticotropin-releasing factor receptor-1 in the conditioned preference place induced by morphine in mice

Pharmacological Reports ◽

10.1016/s1734-1140(11)70485-6 ◽

2011 ◽

Vol 63 (1) ◽

pp. 257-258

Author(s):

Carmen Lasheras ◽

Ana González-Cuello ◽

Maria Victoria Milanés ◽

Maria Luisa Laorden

Keyword(s):

Corticotropin Releasing Factor ◽

Conditioned Preference

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Effect of a central CRF antagonist on cardiovascular and thermoregulatory responses induced by stress or IL-1 beta

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1993.265.4.r834 ◽

1993 ◽

Vol 265 (4) ◽

pp. R834-R839 ◽

Cited By ~ 6

Author(s):

T. Nakamori ◽

A. Morimoto ◽

N. Murakami

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Interleukin 1 ◽

Corticotropin Releasing Factor ◽

Mild Stress ◽

Induced Responses ◽

Interleukin 1 Beta ◽

The Central Nervous System ◽

Beta 2

We investigated the role of central corticotropin-releasing factor (CRF) in the development of cardiovascular and thermal responses induced by stress or by interleukin-1 beta (IL-1 beta) in free-moving rats. Intracerebroventricular (icv) injection of alpha-helical CRF9-41 (10 micrograms), a CRF receptor antagonist, significantly attenuated hypertension, tachycardia, and a rise in body temperature induced by cage-switch stress, a mild stress. However, icv injection of alpha-helical CRF9-41 (10 micrograms) had no effect on hypertension, tachycardia, or fever induced by intraperitoneal (ip) injection of IL-1 beta (2 micrograms/kg) or icv prostaglandin E2 (PGE2, 100 ng). In contrast, icv injection of alpha-helical CRF9-41 (10 micrograms) significantly attenuated hypertension, tachycardia, or fever induced by icv injection of IL-1 beta (20 ng). The present results suggest that central CRF has an important role in the development of the cage-switch stress-induced responses, but it does not seem to contribute to the hypertension, tachycardia, and fever induced by ip IL-1 beta or by central PGE2. However, it is possible that when IL-1 beta directly acts on the central nervous system, some of its actions are mediated by central CRF.

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