Changes in S100B cerebrospinal fluid levels of rats subjected to predator stress.
Predator stress is a type of psychogenic stress induced by an innate recognition of threat. S100B, a calcium-binding protein secreted by astrocytes, has been associated with neurotrophic or neurotoxic action in several neuropsychiatric disorders. It has been recently demonstrated that serum S100B levels in rats are increased after stress by immobilization [S. Scaccianoce, P. Del Bianco, G. Pannitteri, F. Passarelli, Relationship between stress and circulating levels of S100B protein, Brain Res. 1004 (2004) 208-11]. This study aimed to measure cerebrospinal fluid (CSF) S100B in rats after an acute stress situation, which is induced by exposure to a predator. S100B was measured in CSF and in hippocampal and cortical slices by ELISA. Forty-three male Wistar rats, aged 70 days, were randomly assigned to handled (control) or stressed groups (exposed to a cat for 5 min). CSF and brain tissue were removed 1 or 24 h after the procedures. Rats exposed to the cat demonstrated a biphasic change in CSF S100B levels. An increase was observed at 1 h after cat exposure, and a decrease was observed 24 h later, although this was not accompanied by changes in S100B content in hippocampus or cerebral cortex. The effectiveness of the stressor used was confirmed by increased freezing response (during cat exposure) and increased anxiety in the plus maze test (1 h after cat exposure). These results indicate that CSF S100B is changed by stress, reinforcing the possibility that this protein is involved in the adaptive response to stress and/or in secondary neuropsychiatric disorders.
Margis
Regina
R
Department of Psychiatry, Faculty of Medicine, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, 90035-003, Brazil. regina.margis@terra.com.br
Zanatto
Vanessa C
VC
Tramontina
Francine
F
Vinade
Elsa
E
Lhullier
Francisco
F
Portela
Luis V
LV
Souza
Diogo O G
DO
Dalmaz
Carla
C
Kapczinski
Flavio
F
Gonçalves
Carlos-Alberto
CA
D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism; D001923:Brain Chemistry / Q000502:physiology*; D002415:Cats; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D007103:Immobilization / Q000379:methods; D008297:Male; D018782:Maze Learning / Q000502:physiology; D009414:Nerve Growth Factors / Q000134:cerebrospinal fluid*; D011235:Predatory Behavior; D011897:Random Allocation; D051381:Rats; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000134:cerebrospinal fluid*; D013312:Stress, Physiological / Q000134:cerebrospinal fluid*; D013997:Time Factors
D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579158:S100b protein, rat