The NK3 receptor agonist senktide ameliorates scopolamine-induced deficits in memory for object, place and temporal order

Senktide, a potent neurokinin-3 receptor (NK₃-R) agonist, increases acetylcholine (ACh) release in the striatum, the prefrontal cortex (Schäble et al., 2011), the amygdala and hippocampus, presumably via postsynaptic mechanisms. A promnestic action of NK₃-R agonists has been described in a variety of learning/memory tasks. The memory-enhancing effects of NK₃-R agonists and their activating influence on ACh suggest a possible role of the NK₃-R in learning and memory via cholinergic modulation. Deterioration of the cholinergic system in the basal forebrain has been associated with learning and memory deficits and cholinergic agents have promnestic effects in a variety of learning paradigms. The anticholinergic drug, scopolamine, a muscarinic ACh receptor antagonist, incurs deficits in a variety of learning tasks and provides a useful tool to investigate the role of the cholinergic systems in mechanisms underlying learning and memory. The aim of this study was to ascertain the effect of the NK₃-R agonist, senktide, in the scopolamine-induced deficit model. We hypothesized that senktide treatment would attenuate scopolamine-induced (subcutaneous – s.c. 0.75 mg/kg) memory impairment in three novelty preference paradigms based on spontaneous object exploration: namely object recognition, object–place recognition and object recognition for temporal order. Administration of senktide reversed the scopolamine-induced memory deficits by re-establishing object recognition (s.c. 0.2 mg/kg), object–place recognition (0.2 and 0.4 mg/kg), as well as object recognition for temporal order (0.4 mg/kg) in adult Wistar rats. These results indicate memory enhancing effects of senktide in animals subjected to scopolamine-induced memory impairments and indicate that the promnestic action of NK₃-R agonists is mediated by muscarinic cholinergic mechanisms.     

Relative versus absolute stimulus control in the temporal bisection task

When subjects learn to associate two sample durations with two comparison keys, do they learn to associate the keys with the short and long samples (relational hypothesis), or with the specific sample durations (absolute hypothesis)? We exposed 16 pigeons to an ABA design in which phases A and B corresponded to tasks using samples of 1 s and 4 s, or 4 s and 16 s. Across phases, we varied the mapping between the samples and the keys. For group Relative, short and long samples were always associated with the same keys (e.g., Phase A: ‘1s→ Left, 4s→ Right''; Phase B: ‘4s→ Left, 16s→ Right''); for group Absolute, the 4-s sample was associated always with the same key (e.g., Phase A: ‘1s→ Left, 4s→ Right''; Phase B: ‘16s→ Left, 4s→ Right’). If temporal control is relational, group Relative should learn the new task faster than group Absolute, but if temporal control is absolute, the opposite should occur. We compared the results with the predictions of the Learning-to-Time (LeT) model, which accounts for temporal discrimination in terms of absolute stimulus control and stimulus generalization. The acquisition curves of the two groups were generally consistent with LeT and therefore more consistent with the absolute than the relative hypothesis.     

Eating Disorders: A Bond between Medicine,Culture and Psychoanalysis

Action in connection with the therapeutic process is often equated with acting out. The subtle behaviour that belongs to ?the complicated system of transmitting and receiving unconscious signals? (Sandler), with which the patient attempts to make the analyst behave as the object of transference or to fulfill an unconscious desire, is also described as acting out or micro-acting out (Treurniet). This fine-grained action, however, means nothing; it is not symbolic or communicative action. Its intention is, rather, to trigger effects and induce interactions. It occurs not only on the side of the analysand but also on that of the analyst, and is part of the unconscious communication in the therapeutic process. Presented here are some of the various interactive ways and means with which the analyst is prompted into unconscious action and certain, unnoticed, ways in that he turn ?treats? the patient. The analyst's action responses can bear the character of interpretations with which he may unintentionally reveal how he regards the behaviour of the patient.     

Recognition of a 3D snake model and its 2D photographic image by captive black tufted-ear marmosets (Callithrix penicillata)

Two-dimensional (2D) displays of real three-dimensional (3D) objects are frequently used experimental tools in animal studies. Whether marmoset monkeys, with their highly diverse and complex anti-predation strategies, readily recognized 2D representations of potential threats has yet to be determined, as seen in other primates. Thus, the behavioral responses of adult captive black tufted-ear marmosets (Callithrix penicillata) toward an unfamiliar motionless snake-model and its photograph were assessed. Pictorially naïve subjects were randomly divided into two groups (n = 12/each) and submitted to two trials. Group 1 was initially exposed to the 3D object and after 1 week to its photograph. Group 2 was first presented the picture and only tested with the real object 1 week later. All 15-min trials were divided into three consecutive 5-min intervals: pre-exposure, exposure and post-exposure. In the presence of the 3D snake object, regardless of its presentation order, the frequency of direct gazes, head-cocks, tsik-tsik alarm/mobbing calls and genital displays increased significantly. The photograph induced a similar response, although only when the object had been previously presented, as significantly higher levels of these behaviors were seen in Group 1 than Group 2. Proximity to the stimulus, aerial scan, terrestrial glance, displacement activities and locomotion were not consistently influenced by the stimuli’s presence and/or order of presentation. Therefore, marmosets recognized and responded appropriately to biologically and emotionally relevant 3D and 2D stimuli. Since the aversive/fearful reactions toward the photograph were only seen after the snake object had been presented, the former seems to be essentially a learned response.     

The effects of verbal instruction on affective and expectancy learning

The current research assessed the effects of verbal instruction on affective and expectancy learning during repeated contingency reversals (Experiment 1) and during extinction (Experiment 2) in a picture-picture paradigm. Affective and expectancy learning displayed contingency reversal and extinction, but changes were slower for affective learning. Instructions facilitated reversal and extinction of expectancy learning but did not impact on affective learning. These findings suggest a differential susceptibility of affective and expectancy learning to verbal instruction and question previous reports that verbal instructions can accelerate the extinction of non-prepared fear learning in humans.     

Interview with Robert R. Holt by Carlo Bonomi

Abstract

Psychoanalysis had its starting point when in clinical work there arose a new form of listening with regard to the origin of the hysterical symptom. The appraisal of clinical observation is therefore fundamental. At times it inaugurates a new hypothesis or knowledge about the functioning of the mind; at other times it sheds light on a link between clinical work and theory, reaffirming or resulting in new associations about already existing knowledge. Our work lies within the latter proposition, since part of the observation attends to and re-examines certain theoretical aspects. We have begun with the observation that when during the analytical process the issues of castration, of the binomial masculine/feminine, and of separation from the analyst arise, they bring with them, more often than not, the theme “fear of death”. The relationship we attempt to establish between “fear of death” and the assumption of sexuality during analysis are founded on Freud's hypothesis regarding the process of childhood psychosexual development.

Concurrently, when we review Freudian hypothesis about the history of the human race and of primordial man we come across a third plane on which we can make further analogies for the understanding of our attitude once faced with sexuality and death. These theoretical concatenations sanction clinical observation and also serve to elucidate what we might term “the end of analysis”.