F. Vitiello

Some remarks on an experiment suggesting quantum-like behavior of cognitive entities and formulation of an abstract quantum mechanical formalism to describe cognitive entity and its dynamics

We have executed for the first time an experiment on mental observables concluding that there exists equivalence (that is to say, quantum-like behavior) between quantum and cognitive entities. Such result has enabled us to formulate an abstract quantum mechanical formalism that is able to describe cognitive entities and their time dynamics.

Corticotropin-releasing factor triggers neurite outgrowth of a catecholaminergic immortalized neuron via cAMP and MAP kinase signalling pathways.

Corticotropin‐releasing factor (CRF), a neuropeptide of 41 amino acids, acts as the major physiological regulator of the basal and stress‐induced release of corticotropin (ACTH), β‐endorphin and other proopiomelanocortin‐derived peptides from the anterior pituitary gland. In addition to its endocrine activity, CRF displays extrahypophysiotropic effects, mainly as a regulator of stress responses. We show here that CRF may additionally function as a differentiating factor in immortalized noradrenergic neuronal CATH.a cells that express CRF receptor type I and resemble locus coeruleus‐derived neurons. CRF triggers morphological changes in CATH.a cells including the appearence of extended long, slender neurites with prominent growth cones. CRF‐treated CATH.a cells exhibit a morphology similar to locus coeruleus neurons in primary culture. CRF‐induced neurite outgrowth of CATH.a cells was blocked by addition of inhibitors for cAMP‐dependent protein kinase or extracellular signal‐regulated protein kinase (ERK), a subtype of the mitogen‐activated protein kinases. The participation of ERK within the CRF signalling cascade was further confirmed by Western blot experiments, with antibodies directed against the phosphorylated form of ERK, and also with transcription‐based assays. We conclude that CRF functions as a differentiating factor of CATH.a cells via the cAMP and the MAP kinase signalling pathways.

Synapsin-like molecules in Aplysia punctata and Helix pomatia: identification and distribution in the nervous system and during the formation of synaptic contacts in vitro.

The distribution and biochemical features of the synapsin‐like peptides recognized in Aplysia and Helix by various antibodies directed against mammalian synapsins were studied. The peptides can be extracted at low pH and are digested by collagenase; further, they can be phosphorylated by both protein kinase A and Ca2+/calmodulin‐dependent protein kinase II. In the ganglia of both snails, they are associated with the soma of most neurons and with the neuropil; punctate immunostaining is present along the neurites. Using cocultures of a Helix serotoninergic neuron and of its target cell, we analysed the redistribution of the synapsin‐like peptides during the formation of active synaptic contacts. When the presynaptic neuron is plated in isolation, both synapsin and serotonin immunoreactivities are restricted to the distal axonal segments and to the growth cones; in the presence of the target, the formation of a chemical connection is accompanied by redistribution of the synapsin and serotonin immunoreactivities that concentrate in highly fluorescent round spots scattered along the newly grown neurites located close to the target cell. Almost every spot that is stained for serotonin is also positive for synapsin. In the presynaptic cell plated alone, the number of these varicosity‐like structures is substantially stable throughout the whole period; by contrast, when the presynaptic cell synapses the target, their number increases progressively parallel to the increase in the mean amplitude of cumulative excitatory postsynaptic potentials recorded at the same times. The data indicate that mollusc synapsin‐like peptides to some extent resemble their mammalian homologues, although they are not exclusively localized in nerve terminals and their expression strongly correlates with the formation of active synaptic contacts.

Opening/blocking actions of pyruvate kinase antibodies on neuronal and muscular KATP channels

ATP-sensitive-K(+) (KATP) channels couple metabolism to the electrical activity of the cells. This channel is associated with glycolytic enzymes to form complexes regulating the channel activity in various tissues. The pyruvate-kinase (PK) enzyme is an antigen in the Paediatric Autoimmune Neuropsychiatric Disorders Associated Streptococcal infection known as PANDAS which is characterized by an abnormal production of auto-antibodies against PK. Here, the effects of the anti-pyruvate kinase antibody (anti-PK-ab) on the muscle and neuronal KATP channels were investigated in native rat skeletal muscle fibres and human neuroblastoma cell-line (SH-SY5Y), respectively. Furthermore, the interaction of PK with the inwardly rectifier potassium channel (Kir6.1/Kir6.2) subunits of the KATP channels was investigated by co-immunoprecipitation experiments in mouse brain using the anti-PK-ab. Patch-clamp experiments showed that the short-term incubation (1h) of the fibres with the anti-PK-ab at the dilutions of 1:500 and 1:300 enhanced the KATP current of 19.6% and 33.5%, respectively. As opposite, the long-term incubation (24h) of the fibres with the anti-PK-ab at the dilutions of 1:500 and 1:300 reduced the KATP current of 16% and 24%, respectively, reducing the diameter with atrophy. The direct application of the anti-PK-ab to the excised patches in the absence of intracellular ATP caused channel block, while in the presence of nucleotide channel opened. In neuronal cell line, in the short-term the anti-PK-ab potentiated KATP currents without affecting survival, while in the long-term the anti-PK-ab reduced KATP currents inducing neuronal death. Opening/blocking actions of the anti-PK antibodies on the KATP channels were observed, the blocking action causes fibre atrophy and neuronal death. We demonstrated that PK and Kir subunits are physically/functionally coupled in neurons. The KATP/PK complex can be proposed a novel target in the autoimmune diseases associated with anti-PK production as in PANDAS.

Target-dependent modulation of neurotransmitter release in cultured Helix neurons involves adhesion molecules.

The secretory capabilities of the serotonergic neuron C1 of cerebral ganglion of Helix pomatia were markedly reduced when it was cultured in contact with the wrong target neuron, C3. When the neuron B2, one of its physiological targets, was micromanipulated within the network made of intermingled neurites originating from the axonal stumps of both C1 and C3 neurons, C1 increased the amount of the evoked transmitter release, which, after 30 min, reached the level observed when cocultured with the appropriate target. The removal of the appropriate target brought C1 back to the low release condition. By imaging C1 neurites with a fluorescent dye, morphological changes involving a local increase in the number of varicosities could be observed as early as 30 min after contact with the appropriate target. Monoclonal antibody 4E8 against apCAM, a family of Aplysia adhesion molecules, recognizes apCAM‐like molecules of the Helix central nervous system on immunocytochemistry and Western blot analysis. The contact with the appropriate target previously incubated in a 4E8 solution, which did not interfere with its capacity to respond to serotonin, failed to increase the transmitter release of C1 cocultured in the presence of the wrong target, C3. These results suggest that the apCAM‐like antigens bound to the target membrane participate in the molecular processes responsible for the assembly of the “release machinery” present in the functional presynaptic structure. J. Neurosci. Res. 65:111–120, 2001.

Developing rat cerebellum—III Effects of abnormal thyroid states and undernutrition on gangliosides

Alteration of rat postnatal cerebellar development produced by undernutrition, thyroxine treatment and thyroid deficiency also involves ganglioside deposition. The distribution of the different ganglioside types is apparently unaffected but quantitative alterations are present that reflect the reduction of cell number and cell process surface in the adult, and either acceleration or slowing down or reduction of cell formation and maturation occurring during cerebellar development in the three experimental situations.

Developing rat cerebellum. II: Effects of abnormal thyroid states and undernutrition on hyaluronic acid

The early postnatal pattern of hyaluronic acid (HA) deposition in rat cerebellum is affected by thyroid deficiency, thyroxine treatment and undernutrition. The modification of HA ontogenesis apparently reflects the smaller number of cells formed in undernourished rats, or alterations of cell maturation (accelerated in thyroxine‐treated and slowed down in thyroid‐deficient rats). The developmentally regulated:loss of tissue water is also affected in the three conditions; this can be correlated with the roughly simultaneous disappearance of extracellular, but not of total, HA.

Developing rat cerebellum—I. Effects of abnormal thyroid states and undernutrition on sulfated glycosaminoglycans

Sulfated glycosaminoglycans deposition during rat postnatal cerebellar developmental is affected by altered thyroid states and undernutrition. These ontogenetic alterations seem not to be specific but to be one aspect of the general acceleration, slowing down and reduction of the cerebellar development occurring in thyroid‐deficient, hyperthyroid and undernourished rats, respectively.

Ontogenetic changes of the soluble and membrane-bound D2 glycoprotein in rat forebrain

A soluble form of the D2 glycoprotein, detected in the rat brain hypotonic extract, is described. Its specific relative concentration did not differ significantly in the three examined cerebral regions (forebrain, brainstem and cerebellum), while in the cerebellum the membrane‐bound form was about three and four times more concentrated than in the forebrain and brainstem, respectively. No sizeable developmental variations of the soluble D2 concentration could be detected in forebrain, whereas the amount of the membrane‐bound protein rose from birth to postnatal day 6 and then decreased to the adult value (about 40% of the newborn concentration). Ontogenetic modifications of the membranous D2 glycans (studied through the binding of the molecule to several lectins) occur around postnatal day 18 when the binding to Ricinus communis lectin, specific for galactose, becomes evident. At all ages both soluble and membrane‐bound forms bind to Concanavalin A, specific for mannose and glucose, and to wheat germ agglutinin, specific for N‐acetylglucosamine, while the lack of binding to Ulex europeus lectin suggests the absence of discrete amount of fucose. The results are discussed in relation to the possible involvement of D2 glycoprotein in cell‐to‐cell adhesion.

A novel soluble brain-specific protein (Sy-1). Identification and partial characterization.

A novel brain-specific antigen, called Sy-1, has been identified in whole rat brain hypotonic extracts by means of an antiserum produced in rabbits against the synaptosomal cytosol. Sy-1 is an acidic protein (pI 4.7) present exclusively in a soluble form and it does not carry any sugar moiety. Sy-1 is found only in rat brain and, in a partially identical form, in mouse brain. In rat brain the antigen is more concentrated in the brainstem than in the forebrain and cerebellum. On the basis of immunological, physico-chemical and biological criteria Sy-1 differs from other, already described, brain-specific proteins.