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Microglial activation occurs in the absence of anxiety-like behavior following microembolic stroke in female, but not male, rats.

Nemeth CL, Reddy R, Bekhbat M, Bailey J, Neigh GN - J Neuroinflammation (2014)

Bottom Line: The incidence of depression and anxiety disorders is twice as high in women than men; however, females exhibit less neuronal damage following an equivalent ischemic event.The data presented demonstrate that anxiety-like behavior is increased in males despite a comparable increase in microglial activation following microembolic stroke in both males and females.These data suggest that males may be more behaviorally susceptible to the effects of microembolic stroke and further illustrate a dissociation between neuroinflammation and behavior in females.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry and Behavioral Science, Emory University, Atlanta, GA, USA. clnemet@emory.edu.

ABSTRACT

Background: The incidence of depression and anxiety disorders is twice as high in women than men; however, females exhibit less neuronal damage following an equivalent ischemic event. Microembolic stroke increases anxiety- and depressive-like behaviors in male rats but the behavioral repercussions in females are unknown.

Findings: Given the relative neuronal protection from stroke in ovary-intact females, female rats exposed to microembolic stroke may be behaviorally protected as compared to males. The data presented demonstrate that anxiety-like behavior is increased in males despite a comparable increase in microglial activation following microembolic stroke in both males and females.

Conclusions: These data suggest that males may be more behaviorally susceptible to the effects of microembolic stroke and further illustrate a dissociation between neuroinflammation and behavior in females.

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Related in: MedlinePlus

Male and female sham and microsphere embolism (ME) rats were run in a 5-minute elevated plus maze. (A) Total distance traveled of male and female sham and ME rats indicated a significant effect of sex, such that female rats traveled more overall as compared to male rats (P <0.05). (B) A significant interaction between sex and surgery was detected in the elevated plus maze: specifically, compared to male sham, male ME rats spent less time in the open arms of the elevated plus maze, indicative of an anxiety-like state. No difference was detected between female sham and ME rats (P <0.05). (C) Similarly, the number of stretch attend postures were significantly higher in male ME rats compared to both sham and female rats (P <0.05). For all, error bars represent standard error of the mean (SEM) and *indicates P <0.05.
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Fig1: Male and female sham and microsphere embolism (ME) rats were run in a 5-minute elevated plus maze. (A) Total distance traveled of male and female sham and ME rats indicated a significant effect of sex, such that female rats traveled more overall as compared to male rats (P <0.05). (B) A significant interaction between sex and surgery was detected in the elevated plus maze: specifically, compared to male sham, male ME rats spent less time in the open arms of the elevated plus maze, indicative of an anxiety-like state. No difference was detected between female sham and ME rats (P <0.05). (C) Similarly, the number of stretch attend postures were significantly higher in male ME rats compared to both sham and female rats (P <0.05). For all, error bars represent standard error of the mean (SEM) and *indicates P <0.05.

Mentions: The elevated plus maze (EPM) was used as a measure of anxiety-like behavior which consisted of a 5-minute exposure on Day 14 during the animals’ dark cycle. While general locomotor behavior did not differ as a result of ME (P >0.05; Figure 1A), females (sham and ME) were more active in the EPM compared to male rats (F1,36 = 14.92, P <0.05). Furthermore, analysis of time in the open arms of the EPM revealed a significant interaction of sex and surgery, such that ME procedures affected male, but not female, behavior at 2 weeks (F1,43 = 7.140, P <0.05; Figure 1B). Bonferroni posttests revealed a difference between male sham and male ME time spent in the open arms of the maze (mean difference: 49.03 s, P <0.05). Females that underwent the ME procedure did not demonstrate any evidence of increased anxiety-like behavior as defined by differences in time spent in the open arms of the maze, or in stretch attend postures. Conversely, males had an increased display of stretch attend postures compared to sham-operated male and female rats (interaction: F1,42 = 7.004, P <0.05; posttest: mean difference: 12.80, P <0.01; Figure 1C).Figure 1


Microglial activation occurs in the absence of anxiety-like behavior following microembolic stroke in female, but not male, rats.

Nemeth CL, Reddy R, Bekhbat M, Bailey J, Neigh GN - J Neuroinflammation (2014)

Male and female sham and microsphere embolism (ME) rats were run in a 5-minute elevated plus maze. (A) Total distance traveled of male and female sham and ME rats indicated a significant effect of sex, such that female rats traveled more overall as compared to male rats (P <0.05). (B) A significant interaction between sex and surgery was detected in the elevated plus maze: specifically, compared to male sham, male ME rats spent less time in the open arms of the elevated plus maze, indicative of an anxiety-like state. No difference was detected between female sham and ME rats (P <0.05). (C) Similarly, the number of stretch attend postures were significantly higher in male ME rats compared to both sham and female rats (P <0.05). For all, error bars represent standard error of the mean (SEM) and *indicates P <0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4232723&req=5

Fig1: Male and female sham and microsphere embolism (ME) rats were run in a 5-minute elevated plus maze. (A) Total distance traveled of male and female sham and ME rats indicated a significant effect of sex, such that female rats traveled more overall as compared to male rats (P <0.05). (B) A significant interaction between sex and surgery was detected in the elevated plus maze: specifically, compared to male sham, male ME rats spent less time in the open arms of the elevated plus maze, indicative of an anxiety-like state. No difference was detected between female sham and ME rats (P <0.05). (C) Similarly, the number of stretch attend postures were significantly higher in male ME rats compared to both sham and female rats (P <0.05). For all, error bars represent standard error of the mean (SEM) and *indicates P <0.05.
Mentions: The elevated plus maze (EPM) was used as a measure of anxiety-like behavior which consisted of a 5-minute exposure on Day 14 during the animals’ dark cycle. While general locomotor behavior did not differ as a result of ME (P >0.05; Figure 1A), females (sham and ME) were more active in the EPM compared to male rats (F1,36 = 14.92, P <0.05). Furthermore, analysis of time in the open arms of the EPM revealed a significant interaction of sex and surgery, such that ME procedures affected male, but not female, behavior at 2 weeks (F1,43 = 7.140, P <0.05; Figure 1B). Bonferroni posttests revealed a difference between male sham and male ME time spent in the open arms of the maze (mean difference: 49.03 s, P <0.05). Females that underwent the ME procedure did not demonstrate any evidence of increased anxiety-like behavior as defined by differences in time spent in the open arms of the maze, or in stretch attend postures. Conversely, males had an increased display of stretch attend postures compared to sham-operated male and female rats (interaction: F1,42 = 7.004, P <0.05; posttest: mean difference: 12.80, P <0.01; Figure 1C).Figure 1

Bottom Line: The incidence of depression and anxiety disorders is twice as high in women than men; however, females exhibit less neuronal damage following an equivalent ischemic event.The data presented demonstrate that anxiety-like behavior is increased in males despite a comparable increase in microglial activation following microembolic stroke in both males and females.These data suggest that males may be more behaviorally susceptible to the effects of microembolic stroke and further illustrate a dissociation between neuroinflammation and behavior in females.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry and Behavioral Science, Emory University, Atlanta, GA, USA. clnemet@emory.edu.

ABSTRACT

Background: The incidence of depression and anxiety disorders is twice as high in women than men; however, females exhibit less neuronal damage following an equivalent ischemic event. Microembolic stroke increases anxiety- and depressive-like behaviors in male rats but the behavioral repercussions in females are unknown.

Findings: Given the relative neuronal protection from stroke in ovary-intact females, female rats exposed to microembolic stroke may be behaviorally protected as compared to males. The data presented demonstrate that anxiety-like behavior is increased in males despite a comparable increase in microglial activation following microembolic stroke in both males and females.

Conclusions: These data suggest that males may be more behaviorally susceptible to the effects of microembolic stroke and further illustrate a dissociation between neuroinflammation and behavior in females.

Show MeSH
Related in: MedlinePlus