Neuronal Histamine Systems and
Reply to Dr Huston's comment about Poster SAalvarez0117
Edgardo O. Alvarez
Dr. Huston, thanks very much for your comment about our work. I do not think that there is some opposing conclusions about histamine in the central nervous system. The activation of histamine receptors located in different parts of the brain does not necessarily lead to the same biological effects. This is particularly true in the hippocampus. Stimulation of histamine receptors located in the ventral part of the hippocampus produces an inhibitory effect on learning. However, the same stimulation in the hippocampal dorsal part produces an opposing effect (results not published). I think this evidence is revealing how complex can be the physiological role of a neurotransmitter in the brain. Your results on the ventral pallidum are very interesting. We have not worked on this structure so our experience is very limited. It is possible that activation of H1 and H2 histamine receptors here lead to a different final behavioral effect. On the other hand, we have not used the intraventricular route for administering drugs because the cerebrospinal fluid is a direct door to reach many parts of the brain at the same time. Final effects can be viewed as the resultant of the activation of many histamine receptors that can have different and opposing actions.
[ This message was edited on Thu Dec 10 by the author ]
Thu Dec 10