Changes in mRNA expression of alpha1-adrenoceptor subtypes in brain of rats reactive to the chronic mild stress

• Autorzy: Bielawski A. , Zablocka K. , Papp M. , Nalepa I.
• Języki publikacji: EN

Abstrakty

EN

The chronic mild stress (CMS) procedure induces depression-like symptoms in animals. In this model of animals’ depression, rats subjected for a prolonged period of time to a variety of mild stressors gradually decrease their responsiveness to rewarding stimuli (e.g., consumption of sweet pellets). Cerebral alpha1-adrenoceptors (alpha1-AR) are known to be essential for behavioral activation in rodents and changed by stress conditions. Molecular and pharmacological studies revealed the existence of three subtypes of alpha1-AR, named alpha1A, alpha1B and alpha1D. These alpha1-ARs are widely expressed in the brain, though the functional differences among individual subtypes are not clear. We aimed to investigate the expression of alpha1A-, alpha1B- and alpha1D-AR mRNAs in the thalamus, the hippocampus and the prefrontal cortex of rats subjected to the standard CMS procedure. Three groups of male Wistar rats were selected based on behavioral test of sucrose (1 % solution) consumption and were considered in the molecular study: sham, stress reactive and stress non-reactive in the behavioral test. The expression of alpha1-AR mRNAs was measured by quantitative real-time PCR method with the use of TaqMan probes. We found that CMS procedure differently affected the expression of the alpha1-AR mRNAs and the changes were brain structureand receptor subtype-dependent. No changes in expression of three subtypes of alpha1-AR mRNAs was found in the prefrontal cortex. In the thalamus of rats that developed anhedonia to sucrose consumption after the CMS, the expression of all alpha1-AR subtypes was significantly attenuated: the alpha1A mRNA was decreased by 52%, alpha1B - by 55% and alpha1D - by 57% (p<0.05) in the stress reactive animals, while no change in the alpha1-ARs expression was observed in the stress non-reactive animals. In the hippocampus, an opposite direction of change was observed and the effect was limited to the alpha1B-AR mRNA which was increased in the stress reactive group of animals (by 128 %, p<0.5, vs. sham group). Similarly to the thalamus, the alpha1-ARs level in the hippocampus was unchanged in the group of stress non-reactive animals. Our results indicate that CMS induces changes in all subtypes of thalamic alpha1-ARs and suggest the significant impairment of noradrenergic transmission in the thalamus of stress reactive rats. In addition, the hippocampal alpha1B receptor seems to be specifically involved in the phenomenon of response of animals to CMS. Supported by a grant POIG.01.01.02-12-004/09-00 financed by European Regional Development Fund.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2011
• Tom: 71
• Numer: 1
• Opis fizyczny: p.165-166

Twórcy

autor

Bielawski A.

• Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland

autor

Zablocka K.

• Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland

autor

Papp M.

• Laboratory of Behavioral Pharmacology, Department of Pharmacology,Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland

autor

Nalepa I.

• Department of Brain Biochemistry, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland