The crystal structures of two adducts of diphenylmercury with neutral bidentate nitrogen donor atom ligands have been determined, showing very weak interactions between mercury and nitrogen atoms. The crystals are disordered in a manner giving rise to diffuse reflexions for which k is odd. The crystal of diphenylbis-(2,4,7,9-tetramethyl-l,10-phenanthroline)mercury(lI) studied has a=21.09, b= 14.54, c= 14.65 A, beta = 120°34', Z=4, and space group Cm. Crystals of diphenylbis(2,9-dimethyl-l,1O-phenanthroline)mercury(II) have a= 15.42, b= 14.28, c= 14.55 A, alpha~beta~gamma 90°, Z=4,and spacegroup PI with approximate Pm symmetry. Both adducts have their planar ligands in (040) with the C-Hg-C units of Ph2Hg moieties aligned in the [010] direction. Each diphenylmercury moiety has one ligand adjacent to it with Hg-N distances of 2.8-3.0 A, and one-half of the ligands in the crystals do not have a mercury atom adjacent to their nitrogen atoms. Within the unit cell of each adduct every second (040) plane has 0·5 occupancy for two Ph2Hg moieties with mercury atoms in those planes, and every other (040) plane has 0·8 and 0.2 occupancy for two Ph2Hg moieties in those planes, giving one Ph2Hg for every two ligands

Cahill, L

Drysdale, E

Ebmeier, KP

O'Carroll, Ronan Edward

Shajahan, P

The connection between affect and memory is poorly understood. A possible psychopharmacological linking mechanism is the sympathetic arousal that occurs in response to threatening or emotive material. Cahill et al. (1994) reported that a single administration of 40 mg propranolol hydrochloride, a non-selective beta-adrenergic blocker, to healthy young adults significantly reduced delayed recall of emotive material, with recall of matched neutral material unaffected. This study differed importantly from the original Cahill et al. (1994) procedure in that only the emotionally arousing narrative was employed. Using the same slide presentation as Cahill et al. (1994), an experiment was carried out in order to determine whether beta-adrenergic blockade significantly reduces recall of emotive material via a central or peripheral mode of action. Thirty-six healthy young adults were recruited as subjects. Subjects were randomly allocated to three groups: (a) placebo (b) 40 mg propranolol hydrochloride (a beta blocker which readily crosses the blood brain barrier) and (c) 40 mg nadolol (a beta blocker which does not cross the blood-brain barrier). The three groups were matched for age, sex, intelligence, personality factors, and general memory functioning. Subjects viewed a series of 11 slides accompanied by a narrative, divisible into three phases. The emotionally arousing component of the narrative was introduced during phase II. Both central and peripheral beta blockade produced the expected effects on the sympathetic nervous system, as demonstrated by reliable reductions in systolic and diastolic blood pressure. In a surprise memory test 1 week later, subjects were asked to recall as much as possible of the story and slides, and also completed a forced choice recognition memory test. All three groups showed heightened recall and recognition for the central (emotive) section of the story. There was no differential effect of beta blockade (either central or peripheral) relative to placebo. Beta blockade markedly reduced systolic and diastolic blood pressure, but resulted in no significant effect on memory for both emotional and neutral material

O'Carroll, RE

Oxford University Research Archive (ORA)

Journal of Psychopharmacology

Memory for emotional material: a comparison of central versus peripheral beta blockade.

The connection between affect and memory is poorly understood. A possible psychopharmacological linking mechanism is the sympathetic arousal that occurs in response to threatening or emotive material. Cahill et al. (1994) reported that a single administration of 40 mg propranolol hydrochloride, a non-selective beta-adrenergic blocker, to healthy young adults significantly reduced delayed recall of emotive material, with recall of matched neutral material unaffected. This study differed importantly from the original Cahill ct al, (1994) procedure in that only the emotionally arousing narrative was employed. Using the same slide presentation as Cahill et al. (1994), an experiment was carried out in order to determine whether beta-adrenergic blockade significantly reduces recall of emotive material via a central or peripheral mode of action. Thirty-six healthy young adults were recruited as subjects. Subjects were randomly allocated to three groups: (a) placebo (b) 40 mg propranolol hydrochloride (a beta blocker which readily crosses the blood-brain barrier) and (c) 40 mg nadolol (a beta blocker which does not cross the blood-brain barrier). The three groups were matched for age, sex, intelligence, personality factors, and general memory functioning. Subjects viewed a series of 11 slides accompanied by a narrative, divisible into three phases. The emotionally arousing component of the narrative was introduced during phase II. Both central and peripheral beta blockade produced the expected effects on the sympathetic nervous system, as demonstrated by reliable reductions in systolic and diastolic blood pressure. In a surprise memory test I week later, subjects were asked to recall as much as possible of the story and slides, and also completed a forced choice recognition memory test. All three groups showed heightened recall and recognition for the central (emotive) section of the story. There was no differential effect of beta blockade (either central or peripheral) relative to placebo. Beta blockade markedly reduced systolic and diastolic blood pressure, but resulted in no significant effect on memory for both emotional and neutral material.</p

University of St. Andrews - Pure

Memory for emotional material: a comparison of central versus peripeheral beta blockade

A. J. Canty

B. M. Gatehouse

Crossref

Acta Crystallographica Section B

English