MSH/ACTH 4-10 Influences Behavioral and Physiological Measures of Attention¹

Abstract

Eleven healthy male volunteers were infused with MSH/ACTH 4-10 and a control solution in a completely crossed and balanced procedure. Perception, attention and memory were tested as were heart rate and cephalic pulse amplitude in response to changes in the environment. Treatment of subjects with MSH/ACTH 4-10 raised their perceptual threshold for detection of simple stimuli and facilitated perceptual integration of patterned information. Administration of the heptapeptide improved the subjects' ability to discriminate tests of relevant from irrelevant information and augmented the heart-rate deceleratory response during presentation of novel stimuli. It was speculated that MSH/ACTH 4-10 has a predominant influence on attentional processes and that it may be uniquely coded for attentional/perceptual functioning.

Iris pigmentation and behavioral inhibition

“…Both physiological and behavioral research suggest that a-MSH influences mood and emotion. Administration of a-MSH to humans affects cardiac and vascular processes (Aldinger, Hawley, Schally, & Kastin, 1973;Kadowitz, Chap-nick, & Kastin, 1976;Kastin el al.. 1975;Sandman et al, 1977), enhances vagal tone (LaHoste, Olson, Kastin & Olson, 1980), and reduces reports of "state anxiety" (Miller et al, 1974;Sandman, George, Nolan, Van Riezen, & Kastin, 1975). Studies with both humans and animals reveal that a-MSH, which is released in response to a variety of stressors (Dunn, Kastin, Camllo, & Schally, 1972;Kastin et al, 1973;Sandman, Kastin, Schally, Kendall, & Miller, 1973), reduces responsiveness to pain and creates a behavioral profile resembling that produced by the opioid beta-endorphin (P-END) (Walker, Akil, & Watson, 1980).…”

The Pharmacology of Memory: A Neurobiological Perspective

“…This conclu sion is based on failures to observe effects on memory in double-blind, controlled studies of normal volunteers given single infusions of 15-30 mg of ACTH4--10 prior to tests of free recall (88), paired associate learning (89,90), and short-term retention of verbal or nonverbal material (90,91). ACTH-like peptides, however, do seem to affect performance on some tasks requiring detection or vigilance (89,92). Although these effects have been taken to reflect improvement in attentional processes (93,94), this possibil ity has not yet been explored in better-understood paradigms where atten tion in human subjects can be profi tably investigated (95).…”

Oxytocin Increases the Influence of Public Service Advertisements

“…For advertisements that last 30 seconds to two minutes, the likely neurochemical signal of attention is ACTH [9]–[12]. ACTH is a mediator of attention and distress [13]–[15]. It is released in seconds following a stimulus [16] and prepares the organism to act in response to environmental change.…”