Geometroneurodynamics and Neuroscience

The Orthodox Interpretation of quantum mechanics, as developed by many physicists, particularly John von Neumann, addresses the role of measurement, available choices and response of the quantum system to questions posed by an observer in specific quantum laboratory experiments. As such, it is, more consistent and clearer than other interpretations of quantum mechanics and it provides an account of the interactions of observers with the external world. However, in order to explore whether quantum mechanics plays a role in the brain, which is the primary issue, one has to examine the applicability of Hilbert space structure as a valid geometric description of neurodynamics. Here, we re-visit previous work involving the orientation selectivity of neurons, which constructed a type of statistical distance function, in agreement with quantum formalism. This is proportional to the usual distance (or angle) between orientations of the neurons. The equivalence between the statistical distance and the Hilbert-space distance was developed before. As such, it gives rise to the possibility of reanalyzing the issue of measurement and information processing in the brain function, what is termed geometroneurodynamics. Several issues of this geometrical approach are examined and work that needs further development identified, such as measurement and observation, what is Nature and who the observer is, all of course relevant to functions of the brain. Extending Orthodox quantum mechanics to neurodynamics may be the ontological opening to the relevance of universal non-dual Awareness, examined in previous works

The Participating Mind in the Quantum Universe

The Orthodox interpretation of quantum mechanics, which followed the Copenhagen Interpretation but was enhanced by primarily Werner Heisenberg and John von Neumann into a fully developed theory, brought in, among others, the role of measurement, available choices and response of the quantum system. It is, more consistent and clear than other interpretations of quantum mechanics as it provides account of the interactions of observers with the external world. As such, the Orthodox interpretation does a lot more than just account for physical interactions in the atomic world, which was the original goal of quantum mechanics in the early part of the twentieth century. In this article we present several issues that may have been answered or need further development, such as measurement and observation, what is Nature and who the observer is. Extending Orthodox quantum mechanics, leading to universal non-dual Awareness may provide a consistent and integrated view of reality and is consistent with advances in mathematical theory. An issue of paramount importance is what are the philosophical underpinnings or ontological view of the quantum nature of the universe and the role of human minds, observations and choices

Effects of Cannabinoids on Ligand-gated Ion Channels

Phytocannabinoids such as Δ9-tetrahydrocannabinol and cannabidiol, endocannabinoids such as N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol, and synthetic cannabinoids such as CP47,497 and JWH-018 constitute major groups of structurally diverse cannabinoids. Along with these cannabinoids, CB1 and CB2 cannabinoid receptors and enzymes involved in synthesis and degradation of endocannabinoids comprise the major components of the cannabinoid system. Although, cannabinoid receptors are known to be involved in anti-convulsant, anti-nociceptive, anti-psychotic, anti-emetic, and anti-oxidant effects of cannabinoids, in recent years, an increasing number of studies suggest that, at pharmacologically relevant concentrations, these compounds interact with several molecular targets including G-protein coupled receptors, ion channels, and enzymes in a cannabinoid-receptor independent manner. In this report, the direct actions of endo-, phyto-, and synthetic cannabinoids on the functional properties of ligand-gated ion channels and the plausible mechanisms mediating these effects were reviewed and discussed

The Effect of Δ9-tetrahydrocannabinol, Cannabidiol, Menthol and Propofol on 5-hydroxytryptamine Yype 3 Receptors--A Computational Approach

This study investigates the function of 5-HT type 3 (5- HT3) receptors using a computational approach

The Effect of Δ9-tetrahydrocannabinol, Cannabidiol, Menthol and Propofol on 5-hydroxytryptamine Yype 3 Receptors--A Computational Approach

This study investigates the function of 5-HT type 3 (5- HT3) receptors using a computational approach

Inhibition Modifies the Effects of Slow Calcium-Activated Potassium Channels on Epileptiform Activity in a Neuronal Network Model

Generation of epileptiform activity typically results from a change in the balance between network excitation and inhibition. Experimental evidence indicates that alterations of either synaptic activity or intrinsic membrane properties can produce increased network excitation. The slow Ca2+-activated K+ currents (sI AHP) are important modulators of neuronal firing rate and excitability and have important established and potential roles in epileptogenesis. While the effects of changes in sI AHP on individual neuronal excitability are readily studied and well established, the effects of such changes on network behavior are less well known. The experiments here utilize a defined small network model of multicompartment pyramidal cells and an inhibitory interneuron to study the effects of changes in sI AHP on network behavior. The benefits of this model system include the ability to observe activity in all cells in a network and the effects of interactions of multiple simultaneous influences. In the model with no inhibitory interneuron, increasing sI AHP results in progressively decreasing burst activity. Adding an inhibitory interneuron changes the observed effects; at modest inhibitory strengths, increasing sI AHP in all network neurons actually results in increased network bursting (except at very high values). The duration of the burst activity is influenced by the length of delay in a feedback loop, with longer loops resulting in more prolonged bursting. These observations illustrate that the study of potential antiepileptogenic membrane effects must be extended to realistic networks. Network inhibition can dramatically alter the observations seen in pure excitatory networks

The Effect of Changes in the Inhibitory Interneuron Connectivity on the Pattern of Bursting Behavior in a Pyramidal Cell Model

Inhibitory interneurons play crucial roles in the regulation of patterns of activity in the hippocampus, and some types are thought to be vulnerable in epilepsy. The connections between excitatory and inhibitory synapses are important for generation of bursting activity in pyramidal neurons. The present study investigates the influences of changes in the connectivity of interneurons on the patterns of bursting in several excitatory connections using a multicompartmental pyramidal cell model. Simulations show that bursting activity depends upon changes in the connectivity of the inhibitory interneuron, and the location of the inhibitory synapses on excitatory neurons

The Influence of Slow Calcium-Activated Potassium Channels on Epileptiform Activity in a Neuronal Model of Pyramidal Cells

An imbalance between excitation and inhibition can play an important role in the generation of epileptiform activity. Experimental evidence indicates that alterations of either synaptic activity or intrinsic membrane properties may contribute to this imbalance. The slow Ca2+ - activated K+ currents (sIAHP) limit neuronal firing rate and excitability and are therefore of great interest for their potential role in epileptogenesis. The sIAHP is found in both excitatory and inhibitory neurons, and its effect on these neurons can influence the network behavior. Simulations show that the increased excitability caused by reduction of inhibition by the sIAHP for inhibitory interneuron generates recurrent bursting activity

Apigenin and Structurally Related Flavonoids Allosterically Potentiate the Function of Human α7-Nicotinic Acetylcholine Receptors Expressed in SH-EP1 Cells

Phytochemicals, such as monoterpenes, polyphenols, curcuminoids, and flavonoids, are known to have anti-inflammatory, antioxidant, neuroprotective, and procognitive effects. In this study, the effects of several polyhydroxy flavonoids, as derivatives of differently substituted 5,7-dihydroxy-4H-chromen-4-one including apigenin, genistein, luteolin, kaempferol, quercetin, gossypetin, and phloretin with different lipophilicities (cLogP), as well as topological polar surface area (TPSA), were tested for induction of Ca2+ transients by α7 human nicotinic acetylcholine (α7 nACh) receptors expressed in SH-EP1 cells. Apigenin (10 μM) caused a significant potentiation of ACh (30 μM)-induced Ca2+ transients, but did not affect Ca2+ transients induced by high K+ (60 mM) containing solutions. Co-application of apigenin with ACh was equally effective as apigenin preincubation. However, the effect of apigenin significantly diminished by increasing ACh concentrations. The flavonoids tested also potentiated α7 nACh mediated Ca2+ transients with descending potency (highest to lowest) by genistein, gossypetin, kaempferol, luteolin, phloretin, quercetin, and apigenin. The specific binding of α7 nACh receptor antagonist [125I]-bungarotoxin remained unchanged in the presence of any of the tested polyhydroxy flavonoids, suggesting that these compounds act as positive allosteric modulators of the α7-nACh receptor in SH-EP1 cells. These findings suggest a clinical potential for these phytochemicals in the treatment of various human diseases from pain to inflammation and neural disease

The Influences of GABAA and GABAB Inhibition in Bursting Activity in a Model of Pyramidal Cells

This work provides information from the AES Proceedings on epilepsy