PMID- 8457843
OWN - NLM
STAT- MEDLINE
DCOM- 19930426
LR  - 20190614
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 604
IP  - 1-2
DP  - 1993 Feb 26
TI  - Cortical refractoriness to N-methyl-D,L-aspartic acid (NMA) stimulation in the 
      lactating rat: recovery after pup removal and blockade of progesterone receptors.
PG  - 16-23
AB  - We have previously reported that lactating rats, unlike cycling rats, are 
      refractory to N-methyl-D,L-aspartic acid (NMA), but not kainate, in terms of 
      behavioral responses and activation of cFos expression in the neocortex and 
      hippocampus. To study the factors involved in the suppression of cortical 
      activation in lactating rats in response to NMA, we examined the effects of 
      removing either the suckling stimulus and/or progesterone. The degree of cFos 
      expression was used as a marker for cortical activation. Whereas control suckled 
      animals exhibited little or no cFos activation in the piriform cortex in response 
      to NMA, cycling rats showed a high degree of activation. Blockade of the effects 
      of progesterone or removal of the pups for 24 h, resulted in a moderate level of 
      cFos intensity in response to NMA. Total recovery was observed only in animals 
      who had their pups removed for 24 h and the effects of progesterone were blocked. 
      In general, similar results were obtained in the hippocampus except that the 
      total recovery of hippocampal activation took longer than the cortex. Thus, the 
      deficits in cortical activation depend on the presence of both the suckling 
      stimulus and progesterone. However, progesterone alone cannot induce these 
      cortical deficits since pregnant rats showed no deficits in cortical activation 
      in response to NMA when compared to cycling rats. Therefore, the suckling 
      stimulus is required for the inhibition of NMDA-receptor mediated activation of 
      the cortex and hippocampus. The effects of progesterone appear to act 
      synergistically with the effects of suckling.
FAU - Abbud, R
AU  - Abbud R
AD  - Department of Physiology, University of Pittsburgh, School of Medicine 15261.
FAU - Hoffman, G E
AU  - Hoffman GE
FAU - Smith, M S
AU  - Smith MS
LA  - eng
GR  - HD 14643/HD/NICHD NIH HHS/United States
GR  - NS 28730/NS/NINDS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
RN  - 0 (Proto-Oncogene Proteins c-fos)
RN  - 0 (Receptors, Progesterone)
RN  - 320T6RNW1F (Mifepristone)
RN  - 4G7DS2Q64Y (Progesterone)
RN  - 6384-92-5 (N-Methylaspartate)
SB  - IM
GS  - cFos
MH  - Animals
MH  - Cerebral Cortex/drug effects/*physiology
MH  - Female
MH  - Genes, fos/*drug effects
MH  - Hippocampus/drug effects/*physiology
MH  - Immunohistochemistry
MH  - *Lactation
MH  - Mifepristone/pharmacology
MH  - N-Methylaspartate/*pharmacology
MH  - Ovariectomy
MH  - Progesterone/*physiology
MH  - Proto-Oncogene Proteins c-fos/analysis
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Receptors, Progesterone/drug effects/*physiology
EDAT- 1993/02/26 00:00
MHDA- 1993/02/26 00:01
CRDT- 1993/02/26 00:00
PHST- 1993/02/26 00:00 [pubmed]
PHST- 1993/02/26 00:01 [medline]
PHST- 1993/02/26 00:00 [entrez]
AID - 0006-8993(93)90347-P [pii]
AID - 10.1016/0006-8993(93)90347-p [doi]
PST - ppublish
SO  - Brain Res. 1993 Feb 26;604(1-2):16-23. doi: 10.1016/0006-8993(93)90347-p.