Activation of pallidal H receptors induces catalepsy in Wistar rats: A regulatory role of CRF receptors.

An increased concentration of histamine was found in the globus pallidus of parkinsonian patients. The role of this abnormality in the development of parkinsonism is unclear. We examined cataleptogenic activity of histamine injected into the globus pallidus (GP); also, the role of H receptors in histamine effect was evaluated.

Histamine H receptors regulate anhedonic-like behavior in rats: Involvement of the anterior cingulate and lateral entorhinal cortices.

A decreased H receptor activity is observed in the anterior cingulate cortex (aCgCx) of depressed patients. The role of this abnormality in the development of depression-related processes is unstudied. We examined the influence of a decreased brain H receptor activity on rat behavior in the sucrose preference test.

Anticataleptic activity of nicotine in rats: involvement of the lateral entorhinal cortex.

Rationale: Recently, it was found that cyclosomatostatin-induced catalepsy in middle-aged rats is accompanied by neuronal hypoactivation in the lateral entorhinal cortex (LEntCx); this hypoactivation was reversed by systemic administration of nicotine combined with diphenhydramine. These findings suggest the ability of nicotine to regulate catalepsy and the involvement of the LEntCx in this nicotine effect.

Objectives: The study was aimed to assess whether nicotine alone influences catalepsy when injected into the LEntCx and some other neuroanatomical structures.

Cyclosomatostatin-induced catalepsy in aged rats: Specific change of brain c-Fos protein expression in the lateral entorhinal cortex.

Aging represents the largest risk factor for developing Parkinson's disease (PD); another salient feature of this disorder is a decreased brain levels of somatostatin. Recently, in aged Wistar rats, we simulated the central somatostatinergic deficiency by intracerebroventricular injections of a somatostatin antagonist, cyclosomatostatin (cSST). The treated animals displayed catalepsy, a state that resembles the extrapyramidal signs of Parkinson's disease; young animals were insensitive to cSST.

Neuroanatomical correlates of the inhibition of tremulous jaw movements in rats by a combination of memantine and Δ -tetrahydrocannabinol.

Background And Purpose: Memantine and marijuana smoking have been found to inhibit tremor in parkinsonian patients, although the observed effects were relatively weak. The tremorolytic effects of combinations of memantine and cannabinoids have not been studied. Here, we have evaluated the anti-tremor activity of memantine, Δ -tetrahydrocannabinol (THC) given alone and of their combination.

Antidepressants upregulate c-Fos expression in the lateral entorhinal cortex and hippocampal dorsal subiculum: Study in rats.

Neural circuits involved in the development of depression are currently poorly understood. To provide insight into this issue, we evaluated the influence of seven clinically effective antidepressants on neuronal activity in thirty rat brain areas. Drugs belonging to all major groups of antidepressants (imipramine, reboxetine, fluoxetine, bupropion, mirtazapine, agomelatine, and phenelzine) were examined; since antidepressants typically require weeks of continued administration before they achieve a therapeutic effect, we administered these drugs for 21 days.

Synergistic anticataleptic effect of imipramine and nicotine in a rotenone-induced rat model.

Rationale: Some antidepressants have been previously found to produce anti-parkinsonian effect; nicotine was known to mitigate experimental neurotoxic lesions. The anticataleptic efficacy of antidepressant-nicotine co-administration is unstudied.

Objectives: This work aimed to evaluate anticataleptic action of imipramine-nicotine combination in rotenone model.

Cyclosomatostatin- and haloperidol-induced catalepsy in Wistar rats: Differential responsiveness to sleep deprivation.

Total sleep deprivation (SD) has been found to mitigate motor dysfunctions in Parkinson's disease. Apparently, the similar sensitivity of an animal model for parkinsonism would support the model's validity. Recently, we described catalepsy induced in Wistar rats by somatostatin antagonist, cyclosomatostatin (cSST); this model simulates such a disease-associated abnormality as a fall in brain somatostatin levels.

Brain sites mediating cyclosomatostatin-induced catalepsy in Wistar rats: A specific role for the nigrostriatal system and locus coeruleus.

A decrease in somatostatin activity is observed in the Parkinsonian brain. In recent experiments on rats, we simulated this abnormality by intracerebroventricular injections of a somatostatin antagonist, cyclosomatostatin. The treated animals displayed catalepsy, a state that resembles the extrapyramidal signs of Parkinson's disease.

Somatostatin antagonist induces catalepsy in the aged rat.

Rationale: Extrapyramidal motor signs are the major features of Parkinson's disease (PD). It is unclear whether there is a link between these signs and such PD-associated factors as brain somatostatin deficiency and aging.

Objectives: This study aimed to examine whether an inhibition of the brain somatostatin system can initiate catalepsy, a model of extrapyramidal disorders, in young and aged rats.

Amyloid-beta production in aged guinea pigs: atropine-induced enhancement is reversed by naloxone.

Advanced age, cholinergic deficit, and elevated brain levels of enkephalin are associated with sporadic Alzheimer's disease. The influence of these factors on production of amyloidogenic peptides (Abeta) is uncertain. In the present experiments, the levels of 40/42 amino acid-residue Abeta were measured in the brain cortex of guinea pigs aged 15-16 weeks (young) and 25-26 months (aged).