Anxiogenic drugs

Abrams, J. K., Johnson, P. L., Hay-Schmidt, A. et al. (2005). Serotonergic systems associated with arousal and vigilance behaviors following administration of anxiogenic drugs. Neuroscience 133, 983-97. 

Abrams JK, Johnson PL, Shekhar A, Lowry CA (2002) Different anxiogenic drugs activate a common, topographically distinct subpopulation of serotonergic neiu-ones in the rat dorsal raphe nucleus. Program No 75.1. 2002 abstract viewer/itinerary planner. Society for Neuroscience, Washington, http //sfn.scholarone.eom/itin2002/index.html. Cited 20 December 2004... 

Key words Anxiety, experimental animal models, anxiolytic drugs, anxiogenic drugs, biological psychiatry, exploration. 

Thus, the use of some strains should be avoided as their autism-like behavior may prevent the relevance of this test as a model of anxiety. In performing the social interaction test for screening anxiolytic and anxiogenic drugs, it is suggested that the same two mice are not re-introduced into the same environment together, as this may eliminate the social novelty of the condition, and will affect their test performance. 

Although the role of the increase of DA in the prefrontal cortex for the addictive properties of cocaine and amphetamine is obscure, it is unlikely to be a major one given the lack of addictive liability or psychostimulant properties of antidepressants, that increase DA in the PFCX but not in the NAc (Tanda et al., 1994). Finally, a number of aversive-anxiogenic drugs (e.g. picrotoxin, pentylenetetrazol, beta-carbolines) stimulate in vivo DA transmission in the medial prefrontal cortex but fail to affect DA transmission in the NAc shell (Bassareo et al., 1996). These observations indicate that the property of stimulating DA transmission in the NAc shell is not secondary to generic motivational stimulus properties or to psychostimulant properties of addictive drugs. 

Bassareo V, Tanda G, Petromilli P, Giua C, Di Chiara G (1996) Non-psychostimulant drugs of abuse and anxiogenic drugs activate with differential selectivity dopamine transmission in the nucleus accumbens and in the medial prefrontal cortex of the rat. Psychopharmacology 124 293-299. 

Matsmoto K, Yobimoto K, Huong NT, Abdel-Fattah M, Van Hien T, Watanabe H. Psychological stress-induced enhancement of brain lipid peroxidation via nitric oxide systems and its modulation by anxiolytic and anxiogenic drugs in mice. Brain Res 1999 839 74—84. 

Ultrasonic vocalizations are emitted by rat pups (under the age of 14 days) when they are isolated from their mother, and are thought to reflect anxiety. This measure has proven sensitive to both anxiolytic and anxiogenic manipulation of GABA neurotransmission. However, the early developmental window used is problematic, in that chronic drug administration probably results in a variety of compensatory changes not seen in adulthood, and may alter development of relevant brain systems. Indeed, in contrast to the clinical situation, the antidepressant clomipramine has acute, but not chronic, anxiolytic efficacy in this model. 

These drugs increase synaptic serotonin by selectively blocking the serotonin reuptake transporter. In preclinical and human studies acute doses tend to be anxiogenic (Bell and Nutt 1998) but chronic administration has anxiolytic effects, possibly due to downregulation of presynaptic autoreceptors (Blier et al. 1990). There are five SSRIs widely available citalopram, fluoxetine, fluvoxam-ine, paroxetine and sertraline. Escitalopram, the S-enantiomer of citalopram. 

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