N-Methyl-D-aspartate-induced c-Fos expression is enhanced in the forebrain structures related to emotion in Fyn-deficient mice.
Fyn tyrosine kinase is thought to be involved in the control of neuronal intracellular signal transduction elicited by neurotransmitter stimulation. Emotional disorders, such as fearfulness in Fyn-deficient mice, prompted us to investigate the neural mechanisms that lead to defective emotional expression by using functional neuroanatomical methods. In order to examine the reactivity of a specific neural network to excitatory neurotransmitter administration, we mapped the distribution of c-Fos-immunoreactive neurons after administering N-methyl-D-aspartate (NMDA) to control and mutant mice at the subthreshold dose for seizure induction. The induction of neuronal c-Fos-immunoreactivity by NMDA was enhanced in the Fyn-deficient mice, and there was a much greater increase in immunopositive neurons in certain well-defined areas, such as the amygdaloid medial nuclear subdivisions, hypothalamic paraventricular nucleus, and midbrain periaqueductal gray, of the mutant. NMDA-induced c-Fos expression was attenuated by pretreatment with D-(-)-2-amino-5-phosphonovaleric acid, a competitive NMDA antagonist, both in the control and the mutant mice. These findings suggest that the excitability of the projection system from the amygdala to the hypothalamus and midbrain, the main pathways of emotional expression, is enhanced in Fyn-deficient mice.
Hattori
K
K
Department of Anatomy and Developmental Biology, Chiba University School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Yagi
T
T
Maekawa
M
M
Sato
T
T
Yuasa
S
S
D000679:Amygdala / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D002220:Carbamazepine / Q000494:pharmacology; D004347:Drug Interactions / Q000502:physiology; D004644:Emotions / Q000187:drug effects* / Q000502:physiology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D007031:Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D007150:Immunohistochemistry; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation / Q000502:physiology; D016202:N-Methylaspartate / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010487:Periaqueductal Gray / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000172:deficiency* / Q000235:genetics; D016760:Proto-Oncogene Proteins c-fos / Q000187:drug effects / Q000378:metabolism*; D051076:Proto-Oncogene Proteins c-fyn; D013997:Time Factors
D000927:Anticonvulsants; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D002220:Carbamazepine; D016202:N-Methylaspartate; C494960:Fyn protein, mouse; D051076:Proto-Oncogene Proteins c-fyn