Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

Testimonial Knowledge Without Knowledge of what is Said

This article discusses the following question: what epistemic relation must audiences bear to the content of assertions in order to gain testimonial knowledge? There is a brief discussion of why this issue is of importance, followed by two counterexamples to the most intuitive answer: that in order for an audience to gain testimonial knowledge that p they must know that the speaker has asserted p . It is then suggested that the argument generalises and can be made to work on different sets of assumptions about the conditions for knowledge, and the conditions under which a proposition is asserted.     

An Examination of the Lost-letter Technique1

The results of three investigations of the validity and economics of the lost-letter technique are reported. Although the return rate of the lost-letter technique was higher than in the case of more obtrusive survey techniques involving hand-distributed postcard questionnaires and mail surveys, the more obtrusive survey techniques were more economical to carry out, were more accurate in their predictions of election outcomes, and gave results more highly consistent among themselves than with the results obtained by the lost-letter technique. Furthermore, the results indicated that the act of returning a lost letter may not be strongly affected by the identity of the sender or addressee indicated on the letter.     

Referential Intentions and Communicative Luck

Brian Loar [1976] observed that communicative success with singular terms requires more than correct referent assignment. For communicative success to be achieved, the audience must assign the right referent in the right way. Loar, and others since, took this to motivate Fregean accounts of the semantics of singular terms. Ray Buchanan [2014] has recently responded, maintaining that, although Loar is correct to claim that communicative success with singular terms requires more than correct referent assignment, this is compatible with direct reference approaches, as long as one also endorses an independently motivated Gricean view of communicative intentions. This paper argues that Buchanan's Gricean view cannot account for the full range of Loar cases. In doing so, it aims to explicate the structure of Loar's cases and thus to clarify the conditions that a theory must meet in order to adequately meet his challenge.     

Functional analysis and treatment of the bizarre speech of dually diagnosed adults

Nine behavior-analytic studies, each reporting data for a single participant, have shown that bizarre speech can be maintained by social reinforcement. In the current study, we controlled for a possible referral bias in this literature by including nonreferred participants with dual diagnoses. Functional analyses identified attention functions for 2 participants and nonsocial functions for the others. Noncontingent reinforcement decreased the bizarre speech of both participants who displayed attention-maintained bizarre speech.     

Testimonial worth

Synthese - This paper introduces and argues for the hypothesis that judgments of testimonial worth (that is, judgments of the quality of character an agent displays when testifying) are central to...     

Knowledge-yielding communication

Philosophical Studies - A satisfactory theory of linguistic communication must explain how it is that, through the interpersonal exchange of auditory, visual, and tactile stimuli, the communicative...