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Cannabinoid exposure during zebra finch sensorimotor vocal learning persistently alters expression of endocannabinoid signaling elements and acute agonist responsiveness.

Soderstrom K, Poklis JL, Lichtman AH - BMC Neurosci (2011)

Bottom Line: Previously we have found that cannabinoid treatment of zebra finches during sensorimotor stages of vocal development alters song patterns produced in adulthood.To test this hypothesis we have studied effects of the potent cannabinoid receptor agonist WIN55212-2 (WIN) on endocannabinoid levels and densities of CB1 immunostaining in zebra finch brain.We found that late postnatal WIN treatment caused a long-term global disregulation of both levels of the endocannabinoid, 2-arachidonyl glycerol (2-AG) and densities of CB1 immunostaining across brain regions, while repeated cannabinoid treatment in adults produced few long-term changes in the endogenous cannabinoid system.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA. soderstromk@ecu.edu

ABSTRACT

Background: Previously we have found that cannabinoid treatment of zebra finches during sensorimotor stages of vocal development alters song patterns produced in adulthood. Such persistently altered behavior must be attributable to changes in physiological substrates responsible for song. We are currently working to identify the nature of such physiological changes, and to understand how they contribute to altered vocal learning. One possibility is that developmental agonist exposure results in altered expression of elements of endocannabinoid signaling systems. To test this hypothesis we have studied effects of the potent cannabinoid receptor agonist WIN55212-2 (WIN) on endocannabinoid levels and densities of CB1 immunostaining in zebra finch brain.

Results: We found that late postnatal WIN treatment caused a long-term global disregulation of both levels of the endocannabinoid, 2-arachidonyl glycerol (2-AG) and densities of CB1 immunostaining across brain regions, while repeated cannabinoid treatment in adults produced few long-term changes in the endogenous cannabinoid system.

Conclusions: Our findings indicate that the zebra finch endocannabinoid system is particularly sensitive to exogenous agonist exposure during the critical period of song learning and provide insight into susceptible brain areas.

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Related in: MedlinePlus

Repeated cannabinoid treatment during adulthood alters CB1 immunostaining primarily within vocal-motor-related regions of zebra finch brain (HVC, RA, and DLM). Initial daily treatments over 25 days are indicated by first designations (VEH-, WIN-). Later, single acute treatments are indicated second (-VEH, -WIN, see Table 1). Basal staining levels are increased following repeated WIN exposure in adulthood in (B) HVC, (D) RA, and (F) DLM (compare VEH-VEH to WIN-VEH in these panels). Acute responsiveness is not modified following repeated treatments (compare VEH-WIN and WIN-WIN). Chronic treatment did increase responsiveness within the molecular layer of the cerebellum (double-dagger, panel G) Asterisks indicate differences from VEH-VEH treatment groups (p < 0.05, one-way ANOVA followed by SNK post-tests).
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Figure 2: Repeated cannabinoid treatment during adulthood alters CB1 immunostaining primarily within vocal-motor-related regions of zebra finch brain (HVC, RA, and DLM). Initial daily treatments over 25 days are indicated by first designations (VEH-, WIN-). Later, single acute treatments are indicated second (-VEH, -WIN, see Table 1). Basal staining levels are increased following repeated WIN exposure in adulthood in (B) HVC, (D) RA, and (F) DLM (compare VEH-VEH to WIN-VEH in these panels). Acute responsiveness is not modified following repeated treatments (compare VEH-WIN and WIN-WIN). Chronic treatment did increase responsiveness within the molecular layer of the cerebellum (double-dagger, panel G) Asterisks indicate differences from VEH-VEH treatment groups (p < 0.05, one-way ANOVA followed by SNK post-tests).

Mentions: Relative optical densities of CB1 immunostaining within selected brain regions are summarized by treatment groups in Figures 1 and 2. Persistent effects of chronic, 25-day WIN treatments on CB1 staining densities were assessed by comparing VEH-VEH and WIN-VEH groups. In the case of animals treated during sensorimotor development (Figure 1), repeated daily WIN treatments led to a significant decrease in staining density within all regions except DLM (differences from VEH-VEH group indicated by an asterisk). This contrasts with chronic treatment effects produced in adult animals where chronic WIN treatments either produced no effect (lMAN, Area X, Ov, cerebellum) or increased staining densities (HVC, RA, DLM, see Figure 2).


Cannabinoid exposure during zebra finch sensorimotor vocal learning persistently alters expression of endocannabinoid signaling elements and acute agonist responsiveness.

Soderstrom K, Poklis JL, Lichtman AH - BMC Neurosci (2011)

Repeated cannabinoid treatment during adulthood alters CB1 immunostaining primarily within vocal-motor-related regions of zebra finch brain (HVC, RA, and DLM). Initial daily treatments over 25 days are indicated by first designations (VEH-, WIN-). Later, single acute treatments are indicated second (-VEH, -WIN, see Table 1). Basal staining levels are increased following repeated WIN exposure in adulthood in (B) HVC, (D) RA, and (F) DLM (compare VEH-VEH to WIN-VEH in these panels). Acute responsiveness is not modified following repeated treatments (compare VEH-WIN and WIN-WIN). Chronic treatment did increase responsiveness within the molecular layer of the cerebellum (double-dagger, panel G) Asterisks indicate differences from VEH-VEH treatment groups (p < 0.05, one-way ANOVA followed by SNK post-tests).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3025904&req=5

Figure 2: Repeated cannabinoid treatment during adulthood alters CB1 immunostaining primarily within vocal-motor-related regions of zebra finch brain (HVC, RA, and DLM). Initial daily treatments over 25 days are indicated by first designations (VEH-, WIN-). Later, single acute treatments are indicated second (-VEH, -WIN, see Table 1). Basal staining levels are increased following repeated WIN exposure in adulthood in (B) HVC, (D) RA, and (F) DLM (compare VEH-VEH to WIN-VEH in these panels). Acute responsiveness is not modified following repeated treatments (compare VEH-WIN and WIN-WIN). Chronic treatment did increase responsiveness within the molecular layer of the cerebellum (double-dagger, panel G) Asterisks indicate differences from VEH-VEH treatment groups (p < 0.05, one-way ANOVA followed by SNK post-tests).
Mentions: Relative optical densities of CB1 immunostaining within selected brain regions are summarized by treatment groups in Figures 1 and 2. Persistent effects of chronic, 25-day WIN treatments on CB1 staining densities were assessed by comparing VEH-VEH and WIN-VEH groups. In the case of animals treated during sensorimotor development (Figure 1), repeated daily WIN treatments led to a significant decrease in staining density within all regions except DLM (differences from VEH-VEH group indicated by an asterisk). This contrasts with chronic treatment effects produced in adult animals where chronic WIN treatments either produced no effect (lMAN, Area X, Ov, cerebellum) or increased staining densities (HVC, RA, DLM, see Figure 2).

Bottom Line: Previously we have found that cannabinoid treatment of zebra finches during sensorimotor stages of vocal development alters song patterns produced in adulthood.To test this hypothesis we have studied effects of the potent cannabinoid receptor agonist WIN55212-2 (WIN) on endocannabinoid levels and densities of CB1 immunostaining in zebra finch brain.We found that late postnatal WIN treatment caused a long-term global disregulation of both levels of the endocannabinoid, 2-arachidonyl glycerol (2-AG) and densities of CB1 immunostaining across brain regions, while repeated cannabinoid treatment in adults produced few long-term changes in the endogenous cannabinoid system.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA. soderstromk@ecu.edu

ABSTRACT

Background: Previously we have found that cannabinoid treatment of zebra finches during sensorimotor stages of vocal development alters song patterns produced in adulthood. Such persistently altered behavior must be attributable to changes in physiological substrates responsible for song. We are currently working to identify the nature of such physiological changes, and to understand how they contribute to altered vocal learning. One possibility is that developmental agonist exposure results in altered expression of elements of endocannabinoid signaling systems. To test this hypothesis we have studied effects of the potent cannabinoid receptor agonist WIN55212-2 (WIN) on endocannabinoid levels and densities of CB1 immunostaining in zebra finch brain.

Results: We found that late postnatal WIN treatment caused a long-term global disregulation of both levels of the endocannabinoid, 2-arachidonyl glycerol (2-AG) and densities of CB1 immunostaining across brain regions, while repeated cannabinoid treatment in adults produced few long-term changes in the endogenous cannabinoid system.

Conclusions: Our findings indicate that the zebra finch endocannabinoid system is particularly sensitive to exogenous agonist exposure during the critical period of song learning and provide insight into susceptible brain areas.

Show MeSH
Related in: MedlinePlus