The Drosophila Mutant tetanic Interacts with a Gene Complex Including the Structural Locus of K+ Channels and Shows Altered Dephosphorylation and Learning

The tetanic (tta; X.-52.6) mutation has been isolated on the basis of its sensitivity to extradoses of the normal Shaker gene complex (ShC) where the K+ channel la is encoded. The mutant shows up to threefold elevation of the membrane bound protein phosphatase type 1 (PP1) activity in body extracts, probably due to reduced levels of the PP1 specific inhibitor 2 (I-2). By contrast, PP1 activity in the head is only half of the normal value. In addition, tta fails to perform normally in a negative reinforcement olfactory paradigm. The functional relationships between phosphorylation, K+ currents, phosphatase activity and modulation of synaptic activity during learning and memory are discussed in the light of their possible genetic links.     

Analyzing the Patient's First Name in the Search for Identity

A first name captures indispensable information about its bearer, including aspects of the individual's inner world and approach to the environment, the aspirations and attributions of the name-givers for the individual, and the transferences and countertransferences involving the feelings that a first name evokes. A name is therefore a code waiting to be deciphered that, when explored, can reveal its significance to its bearer. A name can impart multiple meanings; the process of interpreting a name is akin to peeling an onion layered in infinite sequences. This article proposes that an examination of the analysand's first name can be a useful clinical tool in psychoanalytic therapy. An exploration into the origin and meaning of a patient's first name through detailed inquiry and association can serve as a rich source of insight regarding relationships between name and self-identity, and can quickly expand the analytic process.     

Poor Short Term Outcome with a Metal-On-Metal Total Hip Arthroplasty

Metal-on-metal (MoM) bearings for total hip arthroplasty (THA) have come under scrutiny with reports of high failure rates. Clinical outcome studies with several commercially available MoM THA bearings remain unreported. We evaluated 78 consecutive MoM THAs from a single manufacturer in 68 patients. Sixty-six received cobalt–chrome (CoCr) monoblock and 12 received modular titanium acetabular cups with internal CoCr liners. Femoral components were titanium with modular necks. At average 2.1 years postoperatively, 12 THAs (15.4%) demonstrated aseptic failure (10 revisions, 2 revision recommended). All revised hips demonstrated capsular necrosis with positive histology reaction for aseptic lymphocytic vasculitis-associated lesions/adverse local tissue reactions. Prosthetic instability following revision surgery was relatively common. Female gender was a strong risk factor for failure, though smaller cups were not. Both monoblock and modular components fared poorly. Corrosion was frequently observed around the proximal and distal end of the modular femoral necks.     

Ca2+/calmodulin sensitivity may be common to all forms of neural adenylate cyclase

The Ca2+/calmodulin (CaM)-activated adenylate cyclase has been implicated as playing an important associative role in classical conditioning in both Aplysia and Drosophila. Studies of the cyclase in mammalian cerebral cortex have suggested that Ca2+/CaM sensitivity is confined to a subpopulation of total cyclase activity. We investigated the properties of cyclase from Aplysia, rat, and bovine central nervous system membranes by using CaM-Sepharose chromatography. Although only a minority of total cyclase activity bound to the CaM column, both bound and unbound fractions of cyclase from all three species showed comparable stimulation by Ca2+ in the presence of CaM. When solubilized bovine membranes were first depleted of most of their endogenous CaM by prior chromatography, binding to the CaM column was substantially increased and Ca2+ stimulation of the unbound fraction was somewhat reduced. However, this reduction in Ca2+ sensitivity resulted from the loss of Ca2+ sensitivity during prior chromatography, rather than from the more efficient separation of Ca2+-sensitive and -insensitive forms. This finding, together with the fact that we never observed any enrichment for Ca2+ sensitivity in the bound fraction over the level in the starting preparation, suggests that the vast majority of the cyclase present in solubilized central nervous system membranes is Ca2+/CaM-sensitive.     

Benzodiazepine receptors in chick retina: development and cellular localization

Benzodiazepine receptors are present in high concentration in the chick retina. Their pharmacological properties are similar to those of the benzodiazepine receptors present in the brain. The retina receptors appear prior to, as well as during, the period of synaptogenesis. In the newborn chick retina the receptors are localized in the inner synaptic layer, probably on or close to synaptic connections.     

Effects of chlordiazepoxide on single-unit activity in the septal region of the freely moving rat: aversive vs. non-aversive contexts

Evidence suggests that stimuli that have the property of inhibiting fear in a Pavlovian fear conditioning paradigm increase cellular activity in the lateral septum, a result consistent with the idea that the lateral septum is actively involved in the inhibition of fear. The experiments reported here were designed to determine if an anxiolytic drug with fear-inhibiting properties would also increase neuronal activity in the lateral septum in a manner that might relate to its mechanism of action as an anxiolytic. An experiment was performed to compare the effects of the benzodiazepine anxiolytic chlordiazepoxide (CDP) upon single-unit activity in the septal region of the rat brain during Pavlovian aversive conditioning with the effects of CDP in a non-aversive context. During Pavlovian conditioning there was a decrease in unit activity in the more lateral regions of the septum, the dorsolateral and ventrolateral nuclei, when a stimulus signaling footshock (CS+) was presented. This conditioned suppression of unit activity was blocked by an intraperitoneal injection of CDP. Additionally, CDP increased baseline unit activity in these regions in the absence of conditioned stimuli. In the more medial regions of the septum, the intermediate lateral septum, we observed few consistent changes either to the conditioned stimuli or to the drug. In a non-aversive context CDP had either no effect at low to moderate doses, or a suppressant effect at a higher dose. The results support a fear-relief hypothesis of lateral septal functioning and suggest the lateral septum as a possible site for the anxiolytic action of benzodiazepines.