Prepulse inhibition of acoustic startle in spontaneously hypertensive rats.
Prepulse inhibition is modulated by dopaminergic drugs and is disrupted in attention-deficit hyperactivity disorder, as well as mental illnesses such as schizophrenia. Spontaneously hypertensive rats (SHR) have been proposed as an animal model of attention-deficit hyperactivity disorder and show marked alterations of dopaminergic regulation of behaviour. SHR showed significantly lower startle amplitude than Wistar-Kyoto (WKY) rats and Sprague-Dawley (SD) rats, but no difference in startle habituation. Baseline percentage prepulse inhibition was higher in SHR and WKY rats than in SD rats. Treatment with amphetamine caused significant disruption of prepulse inhibition in SHR and WKY rats, but not SD rats. In contrast, treatment with apomorphine caused prepulse-dependent disruption of prepulse inhibition in SD rats only. Both MK-801 and 8-OH-DPAT treatment caused disruption of prepulse inhibition in all three rat strains. This study shows differential changes in startle level and prepulse inhibition in SHR, however these rats are not uniformly different from either WKY rats or SD rats and WKY rats differ in a number of respects from SD rats. In conclusion, these data further reveal altered dopaminergic regulation of behaviour in SHR, but also shows that caution is needed about the control strain used to compare these animals with.
Behavioural Neuroscience Laboratory, Mental Health Research Institute of Victoria, 155 Oak Street, Parkville, Vic. 3052, Australia. mvandenbuuse@mhri.edu.au
Maarten
M
van den Buuse
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000161:Acoustic Stimulation / Q000379:methods; D018663:Adrenergic Agents / Q000494:pharmacology; D000661:Amphetamine / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D004195:Disease Models, Animal; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017207:Rats, Sprague-Dawley; D012022:Reflex, Acoustic / Q000187:drug effects / Q000502:physiology*; D013216:Reflex, Startle / Q000502:physiology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013045:Species Specificity
D018663:Adrenergic Agents; D018491:Dopamine Agonists; D018691:Excitatory Amino Acid Antagonists; D017366:Serotonin Receptor Agonists; D016291:Dizocilpine Maleate; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000661:Amphetamine; D001058:Apomorphine