Rodent AVP, 5-HT and Aggression

Cross references:   Serotonin Metabotropic Receptor 
Rodent Nonapeptides          Rodent Hormone-Nerve Interaction  
Serotonin References           



FINAL SUMMARY
OF FIVE REFERENCES
1994 - 2000


    "Animal studies show that arginine vasopressin facilitates aggression, while serotonin (5-HT) inhibits aggression by blocking the activity of the vasopressin system.


INITIAL SUMMARIES
OF THE REFERENCES

Following are initial summaries of the references. The references are designated by the first words of their title and their year of publication.   

The references themselves follow this list of their initial summaries.
 

Vasopressin and serotonin ... 1994
    "
It is possible that serotonin interacts with AVP to modulate offensive aggression."  

Selective inhibition ... 1996   
   
I didn't understand any of this article.   

Serotonin blocks ... 1996    
    "Furthermore, we also confirmed by in vitro autoradiography that the VLH contains vasopressin V(1) and serotonin 5-HT1B receptors. Therefore, it is possible that serotonin may inhibit AVP-facilitated offensive aggression by acting directly at the level of the VLH as well as at other sites."  

Vasopressin/serotonin ... 1997   
    "
Studies in several species of rodents show that arginine vasopressin (AVP) acting through a V1A receptor facilitates offensive aggression, i.e., the initiation of attacks and bites, whereas serotonin (5-HT) acting through a 5-HT1B receptor inhibits aggressive responding."  

Adolescent stress ... 2000   
    "
Animal studies show that arginine vasopressin facilitates aggression, while serotonin (5-HT) inhibits aggression by blocking the activity of the vasopressin system.  

 

   

THE REFERENCES


Agonistic behaviour (Wiki) 
"In ethology, agonistic behaviour is any social behaviour related to fighting, such as aggressive or submissive behaviours. It explicitly includes behaviours such as subordinance, retreat and conciliation which are functionally and physiologically interrelated with aggressive behaviour, yet fall outside the narrow definition of "aggressive behaviour". " 


Vasopressin and serotonin interactions in the control of agonistic behavior (PubMed)  - 1994   
Only abstract available online. 
"In hamsters, dominant/subordinate relationships are initially determined by overt aggression, but subsequently communicated by flank marking, an arginine vasopressin (AVP)-dependent behavior. ... Microinjection of AVP-receptor antagonist into the anterior hypothalamus (AH) inhibits the aggression of a resident hamster toward an intruder and diminishes aggression between hamsters placed into a neutral arena. Microinjection of AVP into the ventrolateral hypothalamus (VLH) facilitates offensive aggression of a resident toward an intruder. As AVP receptors in the VLH are testosterone-dependent, it is possible that the reduction of aggression observed in castrated hamsters is due to a loss of AVP responsiveness in the VLH. Recent work has focused on the notion that serotonin (5-HT) antagonizes AVP activity in the CNS. The AH and VLH have a high density of 5-HT terminals and binding sites. Indeed, there appear to be 5-HT synapses on AVP neurons in the AH. Microinjection of 5-HT into the AH inhibits AVP-induced flank marking while IP injection of fluoxetine a serotonin reuptake inhibitor inhibits AVP-induced offensive aggression in the VLH. It is possible that serotonin interacts with AVP to modulate offensive aggression." 


Selective inhibition of high voltage-activated L-type and Q-type Ca2+ currents by serotonin in rat melanotrophs (PubMed)  - 1996  
Full length HTML and PDF available online for free.   
My comment:  I didn't understand any of this article. 

Melanotroph (Wiki) 
"A Melanotroph (or melanotrope) is a cell in the pituitary gland which
generates melanocyte-stimulating hormone from its precursor Proopiomelanocortin.
"
 

Serotonin blocks vasopressin-facilitated offensive aggression: Interactions within the ventrolateral hypothalamus of golden hamsters (Goog)  - 1996   
Only abstract available online. 
    "
In golden hamsters, vasopressin (AVP) microinjected within the ventrolateral hypothalamus (VLH) facilitates offensive aggression. As serotonin is known to inhibit offensive aggression, we decided to test whether AVP-facilitated behavior is also inhibited by serotonin treatment. Testosterone-treated male golden hamsters received IP injections of fluoxetine, a serotonin reuptake inhibitor, or vehicle 1 h prior to AVP microinjections within the VLH. The animals were tested for offensive aggression in a resident-intruder model after the microinjections, and the results were compared between groups. Pretreatment with fluoxetine inhibited AVP-facilitated offensive aggression. Only one out of nine fluoxetine-treated animals attacked and bit the intruders, compared to six out of seven vehicle-treated animals. Furthermore, we also confirmed by in vitro autoradiography that the VLH contains vasopressin V(1) and serotonin 5-HT1B receptors. Therefore, it is possible that serotonin may inhibit AVP-facilitated offensive aggression by acting directly at the level of the VLH as well as at other sites.



Vasopressin/serotonin interactions in the anterior
hypothalamus control aggressive behavior (Goog)  - 1997   
Full length PDF available online for free. 
    or   
http://www.jneurosci.org/cgi/content/full/17/11/4331 
Full length HTML online for free.
    "Studies in several species of rodents show that arginine vasopressin (AVP) acting through a V1A receptor facilitates offensive aggression, i.e., the initiation of attacks and bites, whereas serotonin (5-HT) acting through a 5-HT1B receptor inhibits aggressive responding." 
  

Adolescent stress and neural plasticity in hamsters: a vasopressin-serotonin model of inappropriate aggressive behaviour (Goog)  - 2000 
Full length PDF available online for free. 
    "Animal studies show that arginine vasopressin facilitates aggression, while serotonin (5-HT) inhibits aggression by blocking the activity of the vasopressin system. Clinical studies report that subjects with a history of ‘fighting and assault’ show a significant positive correlation between cerebrospinal fluid concentrations of vasopressin and aggression in the presence of a hyporeactive 5-HT system. Thus, in animals and humans, a hyporeactive 5-HT system may result in enhanced vasopressin activity and increased aggression." 
"These results provide evidence in an animal model that stress in the form of threat and attack during adolescence can alter the balance between  vasopressin and 5-HT in the brain, resulting in inappropriate aggressive behaviour in early adulthood." 










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