Rat
Hippocampus and Primary Immune Response
R.
Sheela Devi*, R. M. Anand Sivaprakash and A. Namasivayam
Department of Physiology,
Dr. ALM
Post Graduate Institute of Basic Medical Sciences,
Taramani,
Chennai – 600 113
( Received on Oct 10, 2003)
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Abstract : During immune challenge hippocampal region shows
time-dependent changes in neurotransmitter levels. Hence in the
present study the effect of electrolytic lesion in the
dorsolateral hippocampus (DLH) and ventral hippocampal formation
(VHF) (to create a disturbance in neurotransmitter levels) on
humoral immunity in albino rats has been studied along with
appropriate controls. Haemagglutination titre, IgM and IgG levels
were monitored on the 5th day after an immune challenge by sheep
red blood cells (SRBC) suspension. Antigen challenged lesioned
animals had low circulating antibody titre levels compared with
the controls and their site-specific sham lesioned groups. The IgM
levels were significantly lowered in both DLH and VHF lesioned and
immunized animals compared to their immunized sham groups as well
as immunized controls. However, only immunized VHF lesioned group
showed a significant decrease in IgG level from their immunized
sham group. It was concluded from the results that an intact
hippocampal region is essential for the normal humoral immunity
for the primary immune response in rats. Probably VHF region may
be required for the secondary immune response as indicated by the
alteration in IgG levels in these animals.
Key words :
neuroimmunomodulation
humoral immunity
hippocampus
IgM
IgE
