Functional recovery of taste sensitivity to sodium chloride depends on regeneration of the chorda tympani nerve after transection in the rat.

Chorda tympani nerve (CT) transection (CTX) raises sodium chloride (NaCl) taste detection threshold, but the effect of CT regeneration on NaCl threshold is unknown. This experiment examined whether CT regeneration supports normal NaCl threshold in the rat. Thresholds were measured with a 2-lever operant procedure. Thresholds increased more than 1 order of magnitude after CTX regardless of recovery period length. Postsurgical thresholds in rats with regenerated CTs did not differ from presurgical values. Stimulus adulteration with amiloride raised thresholds in rats with intact or regenerated CTs by about 1 order of magnitude but did not raise thresholds beyond postsurgical levels in rats with transected CTs. Thus, the regenerated CT supports normal NaCl threshold, which is raised by amiloride. Because thresholds remained elevated 62 days after CTX when regeneration was prevented, compensatory processes alone cannot support normal NaCl threshold. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chorda tympani nerve transection, but not amiloride, increases the KCl taste detection threshold in rats.

Water-restricted rats were trained to press one lever after KCl presentation and the other lever after distilled water. Water reinforcement was given after each correct response, and a time-out followed each incorrect response. Rats were trained and tested on KCl stimuli of varying concentrations. Threshold was defined as the KCl concentration corresponding to ? the maximum asymptote of performance for each rat. The geometric mean KCl detection threshold for all rats was 0.033 M KCl. Rats that had the chorda tympani nerve (ChT) bilaterally transected showed an average increase in KCl threshold of approximately 0.60 log?? units, whereas sham-operated rats showed no change. Control rats retested with 100 μM amiloride added to all KCl concentrations and water displayed no change in threshold. These results suggest that although the ChT contributes significantly to the rat's sensitivity to KCl, amiloride-sensitive taste transduction pathways do not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral mechanisms for active maternal potentiation of isolation calling in rat pups.

The ultrasonic vocalization (USV) response of the isolated infant rat is a promising model for studying the neurobiology of an early anxiety state, and potentiation of the USV response after brief maternal encounters is a newly discovered behavioral regulator of this state. Using experimental variations in the contexts and patterns of maternal behavior during pup encounters and manual simulations of maternal behavior, we have identified several specific mother–pup interactions that cause potentiation. When one of these, pup carrying, was manually simulated, potentiation followed only if a characteristic postural transport response had been fully expressed by the pup. These behavioral mechanisms and other data suggest hypotheses for the development and adaptive role of maternal potentiation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Formulation,Characterization and Cytotoxicity Effects of Novel Thymoquinone-PLGA-PF68 Nanoparticles

Thymoquinone has anti-cancer properties. However, its application for clinical use is limited due to its volatile characteristics. The current study aims to develop a polymeric nanoformulation with PLGA-PEG and Pluronics F68 as encapsulants to conserve thymoquinone’s (TQ) biological activity before reaching the target sites. Synthesis of nanoparticles was successfully completed by encapsulating TQ with polymeric poly (D, L-lactide-co-glycolide)-block-poly (ethylene glycol) and Pluronics F68 (TQ-PLGA-PF68) using an emulsion–solvent evaporation technique. The size and encapsulation efficiency of TQ-PLGA-PF68 nanoparticles were 76.92 ± 27.38 nm and 94%, respectively. TQ released from these encapsulants showed a biphasic released pattern. Cytotoxicity activity showed that tamoxifen-resistant (TamR) MCF-7 breast cancer cells required a higher concentration of TQ-PLGA-PF68 nanoparticles than the parental MCF-7 cells to achieve IC₅₀ (p < 0.05). The other two resistant subtypes (TamR UACC732 inflammatory breast carcinoma and paclitaxel-resistant (PacR) MDA-MB 231 triple-negative breast cell line) required a lower concentration of TQ-PLGA-PF68 nanoparticles compared to their respective parental cell lines (p < 0.05). These findings suggest that TQ encapsulation with PLGA-PEG and Pluronics F68 is a promising anti-cancer agent in mitigating breast cancer resistance to chemotherapeutics. In future studies, the anti-cancer activity of TQ-PLGA-PF68 with the standard chemotherapeutic drugs used for breast cancer treatment is recommended.     

Expectations, fulfillment, and morale.

The hypothesis that "either low probability of occurrence of an attractive event, or the actual occurrence of that event, would result in greater satisfaction than high probability, or the non-occurrence of the event" is tested. Among subjects who were actually promoted, at the Maxwell Air Force base, those who perceived the probability of promotion as low, responded more favorably than those who perceived the probability as high. Among those not promoted, the responses of Ss who perceived the probability of promotion as low were more favorable than those who perceived the probability as high. In every analysis made, the people who were promoted responded more favorably than those who were not. 28 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Is clinical psychology a science?": Comment.

Comments on an article by Carlton Berenda titled Is clinical psychology a science? (see record 1959-03759-001). As one who aligns himself firmly with those who hold the view that much of clinical psychology and most of psychoanalysis is "obscure and poetic" fabrication, I should like to suggest that in his discussion Berenda apparently has overlooked and failed to take into account perhaps the most crucial issue upon which is based this negative evaluation: that of empirical verification of predicted consequences. Apart from any other errors and misconceptions that may stem from such an omission, this unfortunate oversight leads Berenda with relentless logic to the inescapable assumption of a rather weird and obviously untenable position of subjective relativism as well as to the promulgation of a strangely naive and equally indefensible rationalism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parabrachial gustatory lesions impair taste aversion learning in rats.

Lesions in the gustatory zone of the parabrachial nuclei (PBN) severely impair acquisition of a conditioned taste aversion (CTA) in rats. To test whether this deficit has a memorial basis, 15 intact rats and 10 rats with PBN lesions (PBNX) received 7 intraoral taste stimulus infusions (30 sec, 0.5 ml) distributed over a 30.5-min period after either LiCl or NaCl injection. This task measures the rapid formation of a CTA and has minimum demands on memory. LiCl-injected intact rats progressively changed their oromotor response profiles from one of ingestion to one of aversion. NaCl-injected intact rats did not change their ingestive pattern of responding. In contrast, there was no difference between LiCl- and NaCl-injected PBNX rats. These same PBNX rats failed to avoid licking the taste stimulus when tested in a different paradigm. A simple impairment in a memorial process is not likely the basis for the CTA deficit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)