title: Antidepressant-like effect of cannabidiol injection into the ventral medial prefrontal cortex-Possible involvement of 5-HT1A and CB1 receptors.
abstract: BACKGROUND
  Systemic administration of cannabidiol (CBD), the main non-psychotomimetic constituent of Cannabis sativa, induces antidepressant-like effects. The mechanism of action of CBD is thought to involve the activation of 5-HT1A receptors and the modulation of endocannabinoid levels with subsequent CB1 activation. The brain regions involved in CBD-induced antidepressant-like effects remain unknown. The ventral medial prefrontal cortex (vmPFC), which includes the infralimbic (IL) and prelimbic (PL) subregions, receives dense serotonergic innervation and plays a significant role in stress responses.
  
  
  OBJECTIVE
  To test the hypothesis that the administration of CBD into the IL or PL would induce an antidepressant-like effect through 5-HT1A and CB1 activation.
  
  
  METHODS
  Rats received intra-IL or -PL microinjections of CBD (10-60 nmol/side), 8-OH-DPAT (5-HT1A agonist, 5-10 nmol/side), anandamide (AEA, 0.5 pmol/side) or vehicle (0.2 μl/side) and were submitted to the forced swimming (FST) or to the open field (OFT) tests. Independent CBD-treated groups were pre-treated with WAY100635 (10, 30 nmol/side, 5-HT1A antagonist) or AM251 (10 pmol/side, CB1 antagonist) and submitted to the same tests. An additional group was treated with WAY100635 followed by anandamide.
  
  
  RESULTS
  CBD (PL: 10-60 nmol; IL:45-60 nmol) and 8-OH-DPAT (10 nmol) administration significantly reduced the immobility time in the FST, without changing locomotor activity in the OFT. WAY100635 (30 nmol) did not induce effect per se but blocked CBD, 8-OH-DPAT and AEA effects. Additionally, AM251 blocked CBD-effects.
  
  
  CONCLUSIONS
  administration of CBD into the vmPFC induces antidepressant-like effects possibly through indirect activation of CB1 and 5-HT1A receptors.
authors.affiliation: Department of Physical and Chemical, School of Pharmaceutical Science of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: A G
authors.initials: AG
authors.lastname: Sartim
authors.affiliation: Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of São Paulo, Brazil.
authors.forename: F S
authors.initials: FS
authors.lastname: Guimarães
authors.affiliation: Department of Physical and Chemical, School of Pharmaceutical Science of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), University of São Paulo, Brazil. Electronic address: samia@usp.br.
authors.forename: S R L
authors.initials: SR
authors.lastname: Joca
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000008:administration & dosage; D000818:Animals; D000928:Antidepressive Agents / Q000008:administration & dosage*; D001095:Arachidonic Acids / Q000008:administration & dosage; D001522:Behavior, Animal / Q000187:drug effects*; D002185:Cannabidiol / Q000008:administration & dosage*; D063388:Endocannabinoids / Q000008:administration & dosage; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D010879:Piperazines; D010880:Piperidines / Q000008:administration & dosage; D053284:Polyunsaturated Alkamides / Q000008:administration & dosage; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000502:physiology*; D011720:Pyrazoles / Q000008:administration & dosage; D011725:Pyridines; D051381:Rats; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D044282:Receptor, Serotonin, 5-HT1A / Q000502:physiology*; D058825:Serotonin 5-HT1 Receptor Agonists / Q000008:administration & dosage; D012702:Serotonin Antagonists / Q000008:administration & dosage
chemical_list: D000928:Antidepressive Agents; D001095:Arachidonic Acids; D063388:Endocannabinoids; D010879:Piperazines; D010880:Piperidines; D053284:Polyunsaturated Alkamides; D011720:Pyrazoles; D011725:Pyridines; D043884:Receptor, Cannabinoid, CB1; D058825:Serotonin 5-HT1 Receptor Agonists; D012702:Serotonin Antagonists; D044282:Receptor, Serotonin, 5-HT1A; D002185:Cannabidiol; C103505:AM 251; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C078814:anandamide
keywords: 5HT1A; Antidepressant; Cannabidiol; Forced swimming test; vmPFC