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Elevated expression of alpha1-adrenoceptor subtypes in the hippocampus of rats non-responding to imipramine treatment in the chronic mild stress

100%

Bielawski A., Kowalska M., Papp M., Nalepa L.

Acta Neurobiologiae Experimentalis

2009

tom 69

nr 3

Cerebral α1-adrenoceptors (α1-AR) are known to be changed by stress conditions and involved inthe mechanism of antidepressant action. The chronic mild stress (CMS) procedure that induces depression-like symptoms in animals is a useful tool to study the mechanisms of action of antidepressant drugs in animals. We aimed to investigate the expression of α1A-, α1B-, and α1D-AR mRNAs in the hippocampus of rats subjected to the standard CMS procedure and then treated with an antidepressant drug, imipramine (IMI). Five groups of male Wistar rats were considered in the study: sham-saline; stress-saline; sham-IMI; stress-IMI and IMI-non-responders (i.e., stressed rats, which did not respond to IMI treatment). The expression of α1-ARs was measured at the level of mRNA (by quantitative real-time PCR) and their total density analyzed by [3H]prazosin autoradiography. We found that both CMS procedure and IMI-treatment did not affect the expression of all α1-AR mRNAs. However, in rats non-responding to IMI treatment in behavioral test, the expression of α1A- , α1B- and α1D-AR mRNAs was signifi cantly increased (respectively, by 81%, P<0.01 78%, P<0.01; 46%, P<0.5) compared to sham-saline and stressIMI groups. Similar direction of change was seen in α1-AR total density. Our results suggest the involvement of all subtypes of α1- adrenoceptor in the phenomenon of resistance of depressive animal to IMI treatment. Supported by statutory funds of the Institute of Pharmacology, PAS.

Imipramine-reversed elevation of Hsp72 expression in the brain of rats in the chronic mild stress model of depression

88%

Bielawski A., Zelek-Molik A., Papp M., Kowalska M., Nalepa L.

Acta Neurobiologiae Experimentalis

2013

tom 73

nr Suppl.1

Heat shock proteins HSP70 play a protective role against stressinduced damage of cells. We assessed the expression of inducible Hsp72 in the prefrontal cortex (PFC) and hippocampus (HIP) of male Wistar rats subjected to the chronic mild stress (CMS), the procedure inducing depression-like symptoms, and subsequently Different brain areas are thought to be integrated into largescale networks. Recent approaches for investigating structural organization and functional coordination within these networks involve measures of connectivity among brain areas. Transcranial magnetic stimulation (TMS) can be used to analyze the functional state of the cerebral cortex, discovering changes in its excitability, connectivity and plasticity which may have occurred through processes such as learning or recovery from a lesion. We review studies using in vivo functional brain connectivity technologies. TMS-EEG studies have begun to describe the nature of the TMS-evoked EEG responses in order to broaden the comprehension of the activation mechanisms of TMS. Several studies have proved the power of TMS-EEG by displaying many data about the excitability or connectivity of the brain. Particularly, it has been proposed that the very first part of the TMS evoked EEG response displays the excitability of the stimulated cortex while its spatio-temporal distribution over the scalp displays the spread of activation to other cortical areas – via intra and inter-hemispheric cortico-cortical connections as well as to sub-cortical structures and spinal cord via projection fibres – that means the effective connectivity of the stimulated area. Finally effective connectivity may be considered as the union of structural and functional connectivity. These studies provide insights into the relationships between brain structure and function.

Ograniczanie wyników

2 Acta Neurobiologiae Experimentalis

2 Bielawski A.

2 Kowalska M.

2 Nalepa L.

2 Papp M.

1 Zelek-Molik A.

1 2013

1 2009

Wyniki wyszukiwania

Elevated expression of alpha1-adrenoceptor subtypes in the hippocampus of rats non-responding to imipramine treatment in the chronic mild stress

Imipramine-reversed elevation of Hsp72 expression in the brain of rats in the chronic mild stress model of depression