Resumo de aquém e além do cérebro de Fernando Lopes da Silva

Trabalhou e Viveu no Porto, médico, cientista, professor, investigador, artista plástico, prosador, profundamente humanístico e amante da filantropia, bem como um resistente ao regime salazarista Português. A sua tese de medicina "ensaio de psicologia filosófica" reflete em grande parte os valores que levava na alma, publica enquanto investigador 113 trabalhos científicos, após a sua morte Professor Ruy Gomes e um grupo de amigos fundam a Fundação Abel Salazar, dos seus quadros destacam Trapeiras , Feira, Mercado do Anjo, Paisagem, Vale de Albergaria, Mercado da Ribeira, Ao Sol, Nas Galerias Lafayette, Auto retrato, Costureira, Estudo da Tinta da China. Em 1975 é fundado o ICBAS. Em 1926 passa por um esgotamento e uma depressão, nessa altura dedica-se ás artes demonstrando a sua força de carácter. Mas também escreve uma Primavera em Itália, Filosofia da Arte, A morte da fantasia, Notas sobre a arte portuguesa. 

Defende que a biblioteca devia estar aberta no período noturno deixando enquanto Professor aceder alunos à socapa para estudarem.

"O médico que apenas sabe de medicina, nem medicina sabe" 

Abel Salazar  Guimarães 19.07.89 a 29.12.46 em Lisboa vítima de um cancro pulmonar na casa da sua irmã Dulce Salazar, jaz em paz no cemitério do Prado do Repouso

 Da Silva afirma que uma propriedade fundamental da rede neuronal é a capacidade das células trabalharem em sincronia. 

"A fundamental property of a neuronal network is the capacity of the cells of working in synchrony. This depends essencially on the network interconnectivity. Thus groups of neurons may work synchronously as a population due to mutual interations, that may be either excitatory and inhibitory. A network consists typically of such interconnected excitatory and inhibitory populations."

Mas o que acontece quando estas sinapses se dão de forma assíncrona?

Para isso precisamos de conhecer as atividades rítmicas:

"1) alpha rhytms : occur in relaxed awake animals and show a typical reactivity to eyes closure. Although the frequency range of alpha rhytmes overlaps that of sleep spindles, these two types of phenomena differ in a number of aspects. Namely, their distribution over the cortex and thalamus differs also considerably. Our investigations using multiple electrodes arrays placed on the cortical surface, depth intracortical profiles simultaneously with intrathalamic recordings fom several thalamic nuclei revelead that in the visual cortex alpha waves are generate by a current dipole layer centered at the level of the stoma and basal dentrites of the pyramidal neurons of layers IV and V and that the influence of alpha signals recorded from the thalamus (mainly from the pulvinar nucleous) on the cortical rhytms can be conspicuously large, depending on cortical area."

Aqui fica demostrado que os fatores intercoticais jogam um papel importante nas áreas corticais da atividade alfa.

2) Theta rhytmes: The field potentials of the limbic cortex present another thype of rhythmic activity that covers the frequency range between 4 and 12Hz. It is common pratice to call this activity theta rythm. The brain area where RSA (rhytm slow activity) is most apparent is the hippocampus and para-hippocampal region, although it also occurs in other parts of the lymbic system. RSA was incidentally recorded in humans hippocampus (Giaquinto,1975), and clearly demostrated in the hippocampus of freely moving epileptic patients(Arnolds et al., 1980)using spectral analysis. 

So is accepted that huppocampal RSA depends on intact septo-hippocampal circuits. The thetra rythm is controlled by a network of cells extending from the brain steam to the septum/hippocampus. 

What occurs? During theta , tonically discharge cells of the nucleus reticularis pontis oralis activate neurons of the suprammamillary nucleus; the supramammillary nucleus, in turn, converts this steady barrage into a rhythmical pattern of discharge of the medical septum/vertical limb of the diagonal band. 

Conclusion: some neuronal networks can work as pacemakers of RSA. The cholinergic activation is mediated by muscarinic receptors, since it is blocked by atropine. The atropine insensitive RSA, that appears during motor activity involves certainly other processes and depends on other neuromodulating systems.

3) Beta and Gamma rhytms: these relative hight frequency activities occur in a variety of brain areas and may correspond to different physiological and behavioral conditions. We consider here successively the betta/gamma activities of the olfactory cortical areas and the neocortex. The cortical olfactory areas of the basal forebrain are characterized by rhythmic EEG activities with hight frequency components that may extend from 30-60Hz in the cat, or even to higher frequencies in the rabbit (Freeman 1975, Bressler and Freeman 1980), they correspond to the range of gamma activities. 

Conclusion: neuronal activity is modulated in the different olfactory areas when an animal processes olfactory information.  There is a complex dynamics between yhe olfactory bulb, the anterior olfactory nucleous and the prepyriform cortex, that are interconnected by short and long pathways. This implications showed that neuronal networks should not be assumed to be determined only by local properties, but to depend also on the interactions between networks at different locations, throught reentrant circuits, such that new emerging properties arise from these functional assemblies of cortico-cortical and subcortico-cortical systems.

Reflexion: Changes in generalized brain states correspond closely to changes in the degree of synchrony of neuronal networks that can be detected as changes in spectral properties of EEG/MEG signals, mainly in the low frequency range. Experimental evidence indicates that specific brain rythmes, at relativity hight frequencies (betta/gamma range), can play a role in binding distinct neuronal populations such that conscious perception and sensory motor integration can be achieved. Possibly these type of oscillatory activities play also a role in the formation of memory traces and of the core consciousness. Studying the dynamics of brain rhytms , one can follow the course of cognitive functions at the millisecond time scale, what gives to the recording of the EEG/MEG, particularly in combination technique that can provide a fine spatial resolution such as a magnetic resonance imaging (MRI), a special place among techniques now available to analyze neuro-cognitive functions.