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C Castellano

Publications and source records attributed to C Castellano.

At least 55 records · Page 3Linked to original sources
PubMed1993

Strain-dependent effects of post-training GABA receptor agonists and antagonists on memory storage in mice.

Post-training administration of the GABA-A and GABA-B receptor agonists muscimol and baclofen dose-dependently impaired retention of an inhibitory avoidance response in C57 mice, while improving memory consolidation in the DBA strain. By contrast, picrotoxin (blocker of GABA-activated ionophores), bicuculline (GABA-A antagonist) and CGP 35348 (GABA-B antagonist) dose-dependently improved retention in C57 mice and impaired it in DBA mice. These effects cannot be ascribed to non-specific actions of the drugs on retention performance, as the latencies during the retention test of those mice that had not received footshock during the training were not lengthened by the post-training drug administration. The effects on retention performance induced by GABA agonists and antagonists are probably due to an effect on memory consolidation, since they are observed when the drugs are given at short, but not at long, intervals after training. These results are discussed in terms of possible interaction of GABA systems with endogenous opioid and dopamine systems, whose activation has been shown to produce strain-dependent effects on memory processes. The possible utilization of these results for a genetic behavioral approach with recombinant inbred (RI) mice is also considered.

Animals↗
PubMed1993

Facilitation of shuttle-box avoidance behaviour in mice treated with nifedipine in combination with amphetamine.

The dihydropyridine calcium channel antagonist nifedipine, tested in mice of CD-1, C57BL/6 and DBA/2 strains, at doses of 2.5, 5 and 10 mg/kg IP, had no significant effect on shuttle-box avoidance acquisition. Nifedipine also failed to affect performance retention in CD-1 mice subjected to a one-trial passive avoidance task (step-through). While ineffective alone, nifedipine strongly enhanced the shuttle-box avoidance facilitating action of amphetamine (1 and 2 mg/kg IP) in low performing CD-1 mice. The results indicate that although calcium channel blockers do not affect learning in avoidance paradigms in normal animals, they can interfere with the effects of other centrally acting drugs. Calcium antagonists might interfere with neuronal changes induced by amphetamine, but at present it is difficult to explain the strong avoidance facilitation produced by combinations of nifedipine and amphetamine. A possibility that the action of nifedipine on cerebral circulation is involved in the amphetamine-nifedipine interaction cannot be excluded.

Amphetamine↗
PubMed1993

Effects of oxiracetam, physostigmine, and their combination on active and passive avoidance learning in mice.

The nootropic drug oxiracetam (50 and 100 mg/kg) had no effect on one-trial passive avoidance acquisition in CD-1 mice, while the acetylcholinesterase inhibitor physostigmine improved passive avoidance performance at doses of 0.025 and 0.05 mg/kg given either pre- or posttraining. In a multitrial avoidance task (shuttle-box), a consistent tendency to better performance was displayed by mice receiving oxiracetam (50 and 100 mg/kg) or physostigmine (0.01 and 0.025 mg/kg, but not 0.05 mg/kg). Combinations of the two drugs never improved active or passive avoidance performance more than drugs given separately. This indicates no advantage in combining nootropics and anticholinesterase inhibitors to improve learning and memory.

Animals↗
PubMed1993

Interaction of beta-endorphin and GABAergic drugs in the regulation of memory storage.

These experiments examined the interaction of beta-endorphin and GABAergic drugs, administered post-training, in influencing retention of an inhibitory avoidance response. Male CD1 mice were trained in an inhibitory avoidance task, given immediate post-training ip injections and tested 24 h later for retention. beta-Endorphin (0.5, 1.0, or 2.0 micrograms/kg) and muscimol (0.5, 1.0, or 2.0 mg/kg) produced dose-dependent impairment of retention; picrotoxin (0.25, 0.5, or 1.0 mg/kg) and bicuculline (0.1, 0.25, or 0.5 mg/kg) produced dose-dependent enhancement of retention. A low subeffective dose of muscimol (0.5 mg/kg) potentiated the retention-impairing effect of beta-endorphin (1.0 microgram/kg). In addition, concurrent administration of low, subeffective doses of bicuculline (0.1 mg/kg) or picrotoxin (0.25 mg/kg) attenuated the retention-impairing effects of beta-endorphin (1.0 microgram/kg). The findings are consistent with previous evidence indicating that beta-endorphin influences memory through an interaction with GABAergic mechanisms.

Animals↗
PubMed1992

Enhancement by oxiracetam of passive avoidance improvement induced by the presynaptic muscarinic antagonist secoverine in mice.

Post-trial administration of secoverine (0.5, 1 and 2.5 mg/kg), a presynaptic muscarinic blocker, improved retention in mice tested in a passive avoidance task. The nootropic drug oxiracetam (50 mg/kg), given before both acquisition and retention trial, had no effect alone, but significantly enhanced secoverine improving effects. Performance improvements were also found in combining ineffective doses of the two compounds. Even if not necessarily through a direct and specific action, oxiracetam might activate cholinergic function. Thus, performance improvements resulting from the combination of oxiracetam and secoverine may be due to a simultaneous activation of different cholinergic mechanisms.

Animals↗
PubMed1992

Autoradiography of muscarinic cholinergic receptors in cortical and subcortical brain regions of C57BL/6 and DBA/2 mice.

Mice of the inbred strains C57BL/6 and DBA/2 show strain-dependent behavioural differences which have been correlated with variations in brain cholinergic systems. In the present study, the density of muscarinic cholinergic receptors in both strains of mice was determined by autoradiographic methods using [3H]quinuclidinyl benzilate (QNB) and [3H]pirenzepine as ligands. C57BL/6 mice showed a significantly lower [3H]QNB binding level in the frontal cortex by one third as compared to DBA/2 mice. In the striatum and the cholinergic pontomesencephalic nucleus laterodorsalis tegmenti the [3H]QNB binding was lower in C57BL/6 by 28% and 31%, respectively. The [3H]pirenzepine binding level was found to be significantly higher in C57BL/6 temporal cortex (by 22%). These results are discussed in relation to interstrain differences in cholinergic cell density and in the activity of cholinergic enzymes.

Animals↗
PubMed1992

Dose-dependent effect of GM1 ganglioside during development on inhibitory avoidance behaviour in mice: influence of the period of administration.

Groups of C57BL/6 mice were injected intraperitoneally with GM1 monosialoganglioside at different ages during development and subsequently tested for the retention of an inhibitory avoidance task 24 h after training. Results show improvements in inhibitory avoidance retention according to the age of the animals, the doses of GM1 used and the length of treatment. The effective doses ranged from 20 mg/kg for all age groups after 7 days treatment to 280 mg/kg for 6- and 7-week old animals after pre-trial treatment. Six- and 7-week-old mice are more sensitive to GM1 treatment than 5-week-old animals and, with decreasing lengths of treatment, increasing doses of GM1 are needed to improve the performance of the animals. These findings show that short treatment durations can be effective in improving inhibitory avoidance retention as long as the doses of GM1 administered are increased and that animals are more sensitive to the treatment when they are 6 or 7 weeks of age than when they are 5 weeks old.

Animals↗
PubMed1992

Oxiracetam prevents haloperidol-induced passive avoidance impairment in mice.

The nootropic drug oxiracetam (50 mg/kg) prevented passive avoidance impairment induced by posttraining administration of haloperidol (0.25 and 0.5 mg/kg). Conversely, oxiracetam did not antagonize either locomotor depression or suppression of active avoidance responses induced by the dopamine receptor blocking agent. The results indicate that prevention of haloperidol-induced retention impairment, by oxiracetam, may be due to a not yet defined protective action, common to other nootropic agents, on different types of experimental amnesias, rather than to a specific interaction with dopaminergic mechanisms.

Animals↗
PubMed1992

Strain-dependent effects of post-training dopamine receptor agonists and antagonists on memory storage in mice.

Post-training administration of the selective D1 or D2 agonists SKF 38393 and LY 171555 dose dependently impairs retention of an inhibitory avoidance response in DBA/2 mice. In agreement, the selective D1 or D2 antagonists SCH 23390 and (-)-sulpiride improve retention. These effects are opposite to those observed in the C57BL/6 strain, as previously reported. Moreover, B6D2F1 hybrids present a response to SKF 38393, LY 171555, SCH 23390, and (-)-sulpiride that parallels that of the C57BL/6 strain, thus suggesting that the neural mechanisms underlying the effects of DA agonists or antagonists on memory processes may be inherited through a dominant mode of inheritance.

Animals↗
PubMed1991

Amygdala and dorsal hippocampus lesions block the effects of GABAergic drugs on memory storage.

These experiments examined the effects of posttraining systemic administration of the GABAergic agonist muscimol and the GABAergic antagonist bicuculline on retention in mice with bilateral lesions of the amygdala, dorsal hippocampus or caudate nucleus. Unoperated male CD1 mice and mice with either sham lesions or electrolytically induced lesions of these 3 brain regions were trained in a one-trial inhibitory avoidance task and, immediately after training, received i.p. injections of either muscimol, (1.0, 2.0 or 3.0 mg/kg), bicuculline, (0.25, 0.5 or 1.0 mg/kg), or control solutions. Retention was tested 24 h after training. Lesions of the 3 brain regions produced comparable impairment of retention. In the unoperated controls and sham controls muscimol and bicuculline produced dose-dependent impairment and enhancement, respectively, of retention. The drug effects on retention were blocked by lesions of the amygdala and hippocampus, but were not blocked by lesions of the caudate nucleus. These findings are consistent with other recent evidence suggesting that the amygdala and hippocampus are involved in mediating posttraining neuromodulatory influences on memory storage.

Amygdala↗
PubMed1991

D1 and D2 receptor antagonists differently affect cocaine-induced locomotor hyperactivity in the mouse.

Pretreatment with small, per se ineffective doses of the selective D1 antagonist SCH 23390 inhibited hyperactivity induced by cocaine. On the other hand, the classic neuroleptic haloperidol and the selective D2 antagonist metoclopramide prevented the stimulatory effects of cocaine on locomotion only at hypokinetic doses, while the atypical neuroleptic (-)-sulpiride, a selective D2 antagonist, did not produce significant effects when administered at the hypokinetic dose of 12 mg/kg. Finally, at low doses (-)-sulpiride dose-dependently potentiated the locomotor-stimulating effects of cocaine, an effect that is not shared either with haloperidol or with metoclopramide. These results are discussed in terms of different roles of DA receptor subtypes in the modulation of the stimulant effects of cocaine on locomotion.

Animals↗
PubMed1991

Identification of human papillomavirus type 16 in primary and recurrent cervical cancer following radiation therapy.

Formalin-fixed, paraffin-embedded tissue blocks from 13 women with cervical carcinoma that recurred following radiation therapy were evaluated for the presence of human papillomavirus (HPV) by in situ hybridization using ribonucleic acid 35S-labeled probes for HPV types 6, 11, 16, and 18. Ten of thirteen patients also had pretreatment biopsies from their primary tumors available for analysis. HPV 16 was detected in both primary and recurrent lesions in 4 women. In 1 case, HPV was detected in the primary tumor and not in the recurrence. HPV 16 was also present in three recurrent cancers from which primary lesions were not available for probing. Radiation therapy did not alter the hybridization signal strength or pattern, suggesting that the HPV genome copy number was not significantly affected. The persistence of HPV 16 in recurrent cervical carcinoma is consistent with the theory that HPV plays a role in maintaining the malignant state.

Adult↗
PubMed1991

Effects of oxiracetam-nicotine combinations on active and passive avoidance learning in mice.

Tested alone, in CD-1 mice, the nootropic drug oxiracetam (50 mg/kg) improved learning in a multitrial active avoidance task (shuttle-box), but did not affect one-trial passive avoidance acquisition. Nicotine, which was ineffective at the dose of 0.25 mg/kg, improved both active and passive avoidance at the dose of 0.5 mg/kg; 1 mg/kg nicotine still exerted facilitating effects on passive avoidance, but slightly depressed shuttle-box performance. Combinations of oxiracetam and nicotine improved passive avoidance more than either drug given separately. In the active avoidance task, a combination of oxiracetam with the lower dose of nicotine exerted improving effects never observed with nicotine alone, even at higher doses. The nootropic drug also prevented the slight depressant action exerted by 1 mg/kg nicotine. Thus, contrary to what was previously supposed, at least in mice subjected to shuttle-box avoidance training, nicotinic activation does not appear as the main neurochemical mechanism involved in the action of oxiracetam. Perhaps, oxiracetam and nicotine activate different types of cholinergic mechanisms, but it cannot be excluded that other neurotransmitters, particularly catecholamines, may be involved in the avoidance facilitating effects produced by nicotine and by combinations of the two drugs.

Animals↗
PubMed1991

Effects of acute and chronic stress and of genotype on oxotremorine-induced locomotor depression of mice.

The locomotor behavior of unstressed and stressed mice of two inbred strains, DBA/2 and C57/BL6, was investigated. Animals were tested in a toggle-floor box apparatus, 30 min after saline or oxotremorine treatment (ip). A dose of oxotremorine that did not depress the activity of naïve mice (0.01 mg/kg) was chosen. Stressed mice were injected 24 h after either a single 2-h stress session (acute stress) or the last of 14 daily stress sessions of tube restraining (chronic stress). Acute stress did not modify the depressant effect of oxotremorine on locomotor behavior in either strain. On the contrary, chronic stress induced a clear sensitization of DBA but not C57 mice to the depressant effect of oxotremorine. These findings show that chronic stress may result in modifications of the cholinergic function, and its behavioral correlates, and that these changes are modulated by the genetic makeup.

Animals↗
PubMed1991

Oxotremorine attenuates retrograde amnesia induced by post-training administration of the GABAergic agonists muscimol and baclofen.

These experiments examined the involvement of cholinergic influences in the effects of GABAergic drugs on 24-h retention of an inhibitory avoidance response by mice. A first set of experiments confirmed previous findings indicating that post-training injections (ip) of the GABAergic agonists muscimol (1.0 and 2.0 mg/kg) and baclofen (10.0 and 20.0 mg/kg) impaired retention, as well as previous findings indicating that injections of the cholinergic agonist oxotremorine (5.0 and 10.0 micrograms/kg) enhanced retention. The findings of a second set of experiments indicated that the memory-impairing effects of muscimol and baclofen were attenuated by concurrent injections of a low, and otherwise ineffective, dose of oxotremorine (2.5 micrograms/kg). These findings are interpreted as suggesting that GABAergic drugs affect memory storage through influences on cholinergic systems.

Animals↗
PubMed1991

Post-training dopamine receptor agonists and antagonists affect memory storage in mice irrespective of their selectivity for D1 or D2 receptors.

Post-training administration of the selective D1 and D2 agonists SKF 38393 and LY 171555 dose-dependently facilitated retention of an inhibitory avoidance response in mice, while the selective D1 or D2 antagonists SCH 23390 and (-)sulpiride produced an impairment of retention. These effects are not to be ascribed to a nonspecific action of the drugs on retention performance, as the latencies during the retention test of those mice that had not received a footshock during the training were not increased by the post-training drug administration. The effects on retention performance induced by DA agonists and antagonists seem to be due to an effect on memory consolidation, since they have been observed when drugs were given at short, but not at long, periods of time after training. These results showing a similar role of D1 and D2 receptor types on memory storage appear not to be consistent with a body of neuropharmacological, neurophysiological, and behavioral evidence pointing to a different functional role of these types of DA receptors. This discrepancy is discussed in terms of possible involvement of different brain systems, peripheral systems, or possible second messenger processes activated by the two receptor types and leading to similar effects on memory processes.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1991

Quantity of protein deposited on hydrogel contact lenses and its relation to visible protein deposits.

The purposes of this study were to determine if the quantity of protein deposited (QPD) upon hydrogel lenses was affected by enzymatic cleaning and to test the potential relation between QPD and visible protein deposition (VPD) and change. Seventy-four contact lens patients classified as "heavy depositors" wore new lenses for an average of 80 (SD = 32) days. Cleaning and disinfection solutions varied. One lens was cleaned weekly by a papain enzymatic treatment. The distribution of QPD measurements was bimodal and was related to the FDA material for nonionic, low water content lenses (FDA Materials Group no. 1). The mean deposition was 45 micrograms/cm2 (N = 112) compared with that of ionic, high water content lenses (FDA Materials Group no. 4), which was 1010 micrograms/cm2 (N = 30). VPD distributions were the same for the FDA Group no. 1 and no. 4 lenses. Enzymatic treatment did not significantly reduce QPD; however, enzymatic treatment did reduce VPD. Thus QPD and VPD are independent phenomena and possible reasons for this are given.

Adult↗