Decreased postsynaptic dopaminergic and cholinergic functions in the ventrolateral striatum of spontaneously hypertensive rat.
Dopamine and acetylcholine receptor functions in spontaneously hypertensive rats (SHR) and in control progenitor Wistar-Kyoto (WKY) rats were assessed, using dopamine D1-like/D2-like receptor-mediated and acetylcholine receptor-mediated jaw movements as readout parameters. Spontaneous behaviours such as locomotor activity, vacuous chewing, grooming, sniffing and rearing occurred significantly more in SHR than in WKY rats. In the anaesthetised rats, a mixture of SKF 38393 (5 micrograms), a dopamine D1-like receptor agonist, and quinpirole (10 micrograms), a dopamine D2-like receptor agonist, readily produced repetitive jaw movements in WKY rats, but not SHR, when bilaterally injected into the ventrolateral striatum; such injections into the nucleus accumbens shell were ineffective in each strain. Bilateral injections of carbachol (2.5 micrograms each side), an acetylcholine receptor agonist, into the ventrolateral striatum elicited repetitive jaw movements in both SHR and WKY rats, but to a far less degree in SHR. The present study demonstrates that spontaneous behaviours are enhanced in SHR, and that postsynaptic dopamine D1-like/D2-like receptors and acetylcholine receptors in the ventrolateral striatum of SHR are hyposensitive when compared to those of WKY rats.
Fujita
Satoshi
S
Department of Oral and Maxillofacial Surgery, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Tokyo 101-8310, Chiyoda, Japan.
Adachi
Kazunori
K
Lee
Jun
J
Uchida
Takuya
T
Koshikawa
Noriaki
N
Cools
Alexander R
AR
D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology*; D018491:Dopamine Agonists / Q000494:pharmacology; D006973:Hypertension / Q000503:physiopathology*; D007568:Jaw / Q000187:drug effects / Q000502:physiology; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009068:Movement / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D011950:Receptors, Cholinergic / Q000502:physiology*; D011954:Receptors, Dopamine / Q000502:physiology*; D013045:Species Specificity; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D018491:Dopamine Agonists; D011950:Receptors, Cholinergic; D011954:Receptors, Dopamine