Focal attenuation of specific electroencephalographic power over the right parahippocampal region during transcerebral copper screening in living subjects and hemispheric asymmetric voltages in fixed brain tissue

A Transmissive Theory of Brain Function: Implications for Health, Disease, and Consciousness

Identifying a complete, accurate model of brain function would allow neuroscientists and clinicians to make powerful neuropsychological predictions and diagnoses as well as develop more effective treatments to mitigate or reverse neuropathology. The productive model of brain function, which has been dominant in the field for centuries, cannot easily accommodate some higher-order neural processes associated with consciousness and other neuropsychological phenomena. However, in recent years, it has become increasingly evident that the brain is highly receptive to and readily emits electromagnetic (EM) fields and light. Indeed, brain tissues can generate endogenous, complex EM fields and ultraweak photon emissions (UPEs) within the visible and near-visible EM spectra. EM-based neural mechanisms, such as ephaptic coupling and non-visual optical brain signaling, expand canonical neural signaling modalities and are beginning to disrupt conventional models of brain function. Here, we present an evidence-based argument for the existence of brain processes that are caused by the transmission of extracerebral, EM signals and recommend experimental strategies with which to test the hypothesis. We argue for a synthesis of productive and transmissive models of brain function and discuss implications for the study of consciousness, brain health, and disease.

Right cerebral hemispheric sensitivity to pH and physiological ions in fixed post-mortem Wistar rat brains

Post-mortem human neural tissues fixed in ethanol and aldehyde-based solutions express modulated frequency-dependent microvolt potentials when probed by chemical and electrical stimuli. These observations run contrary to the assumption that basic tissue functions are irreversibly impaired upon fixation, in the absence of nutrients and sufficient concentrations of physiological ions. The aim of the current study was to investigate the relative effects of pH and specific charged particles relevant to normal cell physiology upon electric potentials associated with fixed post-mortem rat brain tissue. We identified a positive relationship between the total time the brains had been immersed in ethanol-formalin-acetic acid and high-frequency microvolt potentials within the dorsal right hemisphere of the rat cerebrum. Measuring the pH of the fixative solution surrounding the brains indicated that as time increased, a logarithmic trend toward alkalinity could be observed. Further experiments revealed that high-frequency microvolt potentials were related to pH changes within the right hemisphere only. The right ventral cerebrum displayed a unique response to potassium chloride in ways uncounted for by pH alone. The results suggest that the fixed post-mortem right cerebrum of the rat is particularly sensitive to pH and physiological ions which explains a subset of previous findings with respect to stimulus-response patterns in human coronal brain sections. A concluding hypothesis is presented which suggests that brain tissue expresses material properties independent of metabolic activity though perhaps relevant to living brain function.

Differential responsiveness of the right parahippocampal region to electrical stimulation in fixed human brains: Implications for historical surgical stimulation studies?

If structure dictates function within the living human brain, then the persistence of specific responses to weak electric currents in fixed, deceased brains could reflect "hardwired" properties. Different key structures from the left and right hemispheres of brains that had been fixed for over 20years with ethanol-formalin-acetic acid were stimulated with either 1-Hz, 7-Hz, 10-Hz, 20-Hz, or 30-Hz, sine-wave, square-wave, or pulsed currents while needle-recorded quantitative electroencephalographic responses were obtained. Differential responses occurred only within the right hippocampus and parahippocampal gyrus. The right hippocampus displayed frequency-independent increases in gamma power relative to the left hemispheric homologue. The parahippocampal region responded exclusively to 7-Hz pulsed currents with wideband (8-30Hz) power. These profiles are consistent with dynamic connections associated with memory and consciousness and may partially explain the interactions resultant of pulse type and hemisphere for experiential elicitations during the golden age of surgical stimulations. The results also indicate that there may be an essential "hardwiring" within the human brain that is maintained for decades when it is fixed appropriately.