Neurosci Lett. 1994 Aug 15;177(1-2):1-4.
The role of 5-HT1A serotonin and D2 dopamine receptors in buspirone effects on cortical electrical activity in rats.

Bogdanov NN, Bogdanov MB.

Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences, Moscow, Russia.

The effects of buspirone (5 and 10 mg/kg i.p.), 8-OH-DPAT (0.25 mg/kg) and raclopride (2.5 mg/kg) on the EEG power spectra of the sensorimotor cortex were studied in freely moving rats. Buspirone (5 mg/kg) and 8-OH-DPAT produced selective slowing of the theta-activity. Buspirone (10 mg/kg) produced slowing of the theta-activity and increased the power of the alpha-band (9-11 Hz). Raclopride alone did not influence EEG power spectra. Simultaneous injection of 8-OH-DPAT and raclopride produced marked slowing of the theta-activity and increased the power of the alpha-band. The role of 5 HT1A and D2 dopamine receptors in buspirone effects on cortical electrical activity in rats was discussed.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7824156&dopt=Abstract buspirone Buspar




Pharmacol Biochem Behav. 1994 Nov;49(3):741-6.
Food carrying in rats is blocked by the putative anxiolytic agent buspirone.

Dringenberg HC, Kornelsen RA, Vanderwolf CH.

Neuroscience Program, University of Western Ontario, London, Canada.

The effects of the putative anxiolytic agent buspirone on food-handling behavior of laboratory rats were investigated. Rats trained to travel from a covered shelter to a food source were provided with food pellets of six sizes. Smaller pellets were eaten at the exposed food source, whereas larger pellets were carried back to the shelter for consumption. Subcutaneous administration of buspirone hydrochloride (0.2-2.0 mg/kg) reduced carrying of larger food pellets in a dose-dependent manner. Instead, these pellets were also eaten at the exposed food source. Carrying was maximally suppressed 1 h after drug administration. Handling of smaller pellets, travel times, and eating times were not affected by buspirone. Similar results have previously been obtained with diazepam. Buspirone appears to exert its effects through 5-HT1A and/or dopamine receptors, whereas diazepam interacts with benzodiazepine receptors. Thus, manipulations of distinct transmitter systems may have similar behavioral consequences on the food carrying responses of rats.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7862731&dopt=Abstract buspirone Buspar




Br J Pharmacol. 1994 Oct;113(2):425-30.
Effect of acute administration of the 5-HT1A receptor ligand, lesopitron, on rat cortical 5-HT and dopamine turnover.

Ballarin M, Carceller A, Guitart X.

Neurochemistry Unit, C.N.S. Department, Laboratories Dr. Esteve, Barcelona, Spain.

1. The involvement of presynaptic 5-hydroxytryptamine1A (5-HT1A) autoreceptors in the anxiolytic-like properties of lesopitron (E-4424) (2-(4-[4-(4-chloro-1-pyrazolyl)butyl]-1- piperazinyl)pyrimidine) was studied. Brain microdialysis was used to examine the effect of the drug on the release of 5-hydroxytryptamine (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the frontal cortex of awake, freely moving rats. Moreover, extracellular cortical 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were also studied to assess the possible participation of dopaminergic systems. 2. Lesopitron administered at a dose which induces anxiolytic behavior in rats (30 micrograms kg-1, i.p.) markedly reduced 5-HT levels (to 45% of the basal value) in cortical perfusates, having no effect on 5-HIAA, DOPAC and HVA. The effects of lesopitron were compared with those produced by the anxiolytic, and structurally related compound, buspirone. 3. Buspirone administered at a dose inducing anxiolytic-like effects in rats (5 mg kg-1, i.p.) produced a marked decrease in cortical 5-HT levels (to 20% of the basal value), but in contrast to lesopitron, buspirone produced a pronounced increase in cortical DOPAC (to 300% of the basal value) and HVA (to 400% of the basal value) levels. Buspirone administered at a low dose (30 micrograms kg-1, i.p.) was unable to affect cortical 5-HT levels. 4. To test the hypothesis that the 5-HT decreasing effect of lesopitron could be due to 5-HT1A autoreceptor (somatodendritic)-mediated inhibition of 5-HT neurotransmission, lesopitron was administered locally into the raphe nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

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J Pharm Pharmacol. 1994 Nov;46(11):931-2.
Buspirone and 1-(2-pyrimidinyl)-piperazine attenuate xylazine-induced antinociception in the mouse.

Cao BJ, Li WP.

Department of Pharmacology, Hunan Institute of Pharmaceutical Industry, Changsha, People's Republic of China.

The effects of subcutaneous pretreatment with buspirone and its major metabolite 1-(2-pyrimidinyl)-piperazine (1-PP) on the antinociceptive effect of xylazine were examined using the mouse acetic acid assay. Both buspirone and 1-PP dose-dependently attenuated the antinociceptive action of subcutaneously administered xylazine (0.8 mg kg-1), with ED50 values of 7.3 mg kg-1 for buspirone and 3.4 mg kg-1 for 1-PP. Pretreatment with either buspirone (8 mg kg-1) or 1-PP (4 mg kg-1) increased the antinociceptive ED50 of xylazine 3-4-fold. These data support the involvement of alpha 2-adrenoceptor and 1-PP in the pharmacological activity of buspirone.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7897604&dopt=Abstract buspirone Buspar




Eur J Pharmacol. 1992 Jan 21;210(3):307-13.
Comparison of the effects of buspirone and chlordiazepoxide on differential reinforcement of low rates of response.

Panickar KS, McNaughton N.

Department of Psychology, University of Otago, Dunedin, New Zealand.

Buspirone is a novel agent which is clinically effective as an anxiolytic but which lacks the muscle relaxant, anticonvulsant and sedative effects of classical anxiolytics. It also lacks the full spectrum of action of classical anxiolytics in animal models of anxiety based on shock and novelty. In the present paper the effects of buspirone and chlordiazepoxide were tested on acquisition of differential reinforcement of low rates of response (DRL). This schedule involves the suppression of behaviour by reward omission and has shown consistent effects with classical anxiolytics. Buspirone was tested at doses of 0.3, 1.1 and 3.3 mg/kg i.p. and chlordiazepoxide at 5 and 20 mg/kg. Buspirone produced effects similar to those of chlordiazepoxide on accuracy of DRL responding. However, the size of the observed effects of buspirone was small even in relation to the 5 mg/kg dose of chlordiazepoxide and did not appear to be directly related to dose. Chlordiazepoxide increased overall rate of responding, while buspirone decreased it. Buspirone appears to show only limited conformity with benzodiazepines in animal models of anxiety and this result appears independent of the reinforcer used in the task.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1612104&dopt=Abstract buspirone Buspar




Physiol Behav. 1991 Mar;49(3):603-11.
Effects of septal lesions on fear-potentiated startle, and on the anxiolytic effects of buspirone and diazepam.

Melia KR, Davis M.

Department of Psychology, Yale University, New Haven, CT.

The present study evaluated the effect of septal lesions on baseline startle amplitude, potentiated startle (a measure of conditioned fear), and the ability of either buspirone or diazepam to block potentiated startle. Baseline responding to an acoustic stimulus was obtained for all rats, followed by potentiated startle training (ten light-shock pairings on each of two days). Rats were then given bilateral electrolytic lesions of the septum or sham surgery. Four and seven days following surgery all rats were tested again for baseline startle amplitude. Ten days postsurgery, rats were injected with either 5.0 mg/kg buspirone or vehicle and tested for potentiated startle (increased acoustic startle in the presence of a light previously paired with shock). Five days later septal-lesioned animals were injected with either 5.0 mg/kg of diazepam or vehicle and again tested for potentiated startle. Septal lesions increased baseline startle amplitude significantly, but did not alter the magnitude of potentiated startle or impair the ability of buspirone or diazepam to block potentiated startle. In Experiment 2 rats were trained using the above procedures, and were subsequently given discrete bilateral lesions of the lateral septum or sham surgery. Lateral septal lesions again had no effect on the magnitude of potentiated startle. These findings do not support an involvement of the septum in the inhibition of fear, or in the mediation of the anxiolytic effects of buspirone or diazepam.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1648244&dopt=Abstract buspirone Buspar




Neuropharmacology. 1991 Apr;30(4):299-306.
An ethological study of the effects of buspirone and the 5-HT3 receptor antagonist, BRL 43694 (granisetron) on behaviour during social interactions in female and male mice.

Cutler MG.

Department of Biological Sciences, Glasgow College, Scotland.

Buspirone (12.8 mg/l; 2.3-2.6 mg/kg daily) and the 5-HT3 receptor antagonist, BRL 43694 (granisetron) (40 micrograms/l; 10 micrograms/kg daily), were each given in drinking fluid to male and female DBA/2 mice for 5-10 days. Controls received tap water. Effects on behaviour were examined by ethological procedures during 5 min encounters with unfamiliar BKW partners. One group of DBA/2 males acted as intruders in a resident-intruder paradigm and another group encountered oestrous females in a neutral cage. The DBA/2 females each encountered a group-housed male in a neutral cage. Both buspirone and BRL 43694 decreased flight in females and increased the duration of their active social investigation. In females, BRL 43694 also reduced the occurrence of "scan" and prolonged the bout length of exploration. In male mice, buspirone increased social investigation, including the specific elements "sniff" and "follow" in encounters with female partners, but its only effect on behaviour during encounters with isolated resident males, was to decrease duration of the element, "attend". In males, BRL 43694 did not significantly affect behaviour in heterosexual encounters and had only a slight effect on behaviour during encounters with resident males, decreasing the occurrence of "eat". Overall, these results suggest that records of effects of drugs on flight responses of female mice, in encounters with male partners, may provide a sensitive index of the anxiolytic profile of novel compounds.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1649417&dopt=Abstract buspirone Buspar




J Pharmacol Exp Ther. 1992 May;261(2):513-7.
Increased rates of punished responding produced by buspirone-like compounds in rats.

Sanger DJ.

Synthelabo Recherche (L.E.R.S), Bagneux, France.

Buspirone has been reported to have effects on punished responding in rats which are considerably smaller and less reliable than those produced by benzodiazepines. A recent study, however, found that buspirone and ipsapirone increased operant responding suppressed by a stimulus which preceded unavoidable shock, suggesting that conditioned emotional response protocols may be more sensitive than punishment procedures. This hypothesis was not supported by the results of the present study. The food-reinforced lever pressing of rats was maintained by a multiple VI schedule with punished and unpunished components. The experimental parameters were similar to those used in the previous conditioned emotional response study. The benzodiazepines, chlordiazepoxide and clorazepate, as well as buspirone (at one dose) and ipsapirone (at several doses), increased rates of punished responding. The 5-hydroxytryptamine-1A receptor ligands 8-hydroxy-2-(di-n-propylamino)tetralin and MDL 73005EF did not reliably produce similar effects, although increased rates of punished responding were seen in some animals. Haloperidol, imipramine and idazoxan did not increase punished response rates. Although the increases in punished responding produced by buspirone were smaller than those produced by chlordiazepoxide and clorazepate, the effect of ipsapirone was quantitatively similar to that of the benzodiazepines.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1349641&dopt=Abstract buspirone Buspar