Effect of spinal cord stimulation on tactile hypersensitivity in mononeuropathic rats is potentiated by simultaneous GABA(B) and adenosine receptor activation.
Neuroscience Letters. 247(2-3):183-6, 1998 May 15.
Department of Neurosurgery, Karolinska Institute Center for Pain Research, Karolinska Institute/Hospital, Stockholm, Sweden.
Abstract:
In rats with abnormally low withdrawal thresholds ('allodynia') in one hindpaw induced by a photochemical sciatic lesion, an intrathecal catheter was inserted to the lumber enlargement and an epidural electrode was implanted at T11. I.t. administration of GABA(B) or adenosine A1 receptor agonists (baclofen, R(-)-N6-(2- phenylisopropyl)adenosine (R-PIA)) suppressed allodynia in a dose-dependent fashion. When the two agonists were given together, each in an ineffective dose, there was a normalization of the thresholds. Rats, in which spinal cord stimulation (SCS) could not suppress the allodynia (non-responders), were transformed into SCS-responders by injection of baclofen and R-PIA in low, ineffective doses, combined with SCS. In SCS responding rats, combination of a selective GABA (B) and an adenosine A1 receptor antagonist (CGP 55845, CPT) in low, ineffective doses abolished the SCS-induced threshold normalization. These results indicate that GABAergic and adenosine-dependent mechanisms are involved in the SCS effect and further suggest a strategy for enhancing the therapeutic efficacy of SCS.
Cluj-Napoca Branch of the Academy of Medical Sciences.
The role of nervous mechanisms in the immune response. [Review] [30 refs]
Revue Roumaine de Physiologie. 29(1-2):5-11, 1992 Jan-Jun.
Abstract:
This review presents the results of experimental researches performed in the last decades by Cluj-Napoca physiologists, concerning the role of hypothalamic nervous centers in the triggering of the nonspecific (phagocytic reaction) and specific (primary and secondary) immune response. The following methods aiming to explore the involvement of the hypothalamic vegetative nervous centers have been applied: section of the spinal cord, somatoencephalic humoral isolation with preservation of spinal cord, stimulation or lesions under stereotaxic control of some hypothalamic areas, conditioned reflexes, electroconvulsant shocks. The results show that nervous centers from the tuberal area and from the posterior hypothalamus are involved in the regulation and integration of the immune response considered as a homeostatic function, in connection with a preoptic, anterior and lateral hypothalamic area, with a receptive function to antigens and their endogenous products. The activation of phagocytosis (phagocytic response) can be elicited in dogs by electrical stimulation of the tuberal area and inhibited by section of the spinal cord, or by barbiturates. The specific immune response is moderately neuromodulated for antigens, as heterospecific red cells and more intensely for Salmonella and especially for the influenza virus. These results could allow an integration of other analytical data of cellular and molecular biology of immunity wider functional concept. [References: 30]
