High-Pass Filtering and Dynamic Gain Regulation Enhance Vertical Bursts Transmission along the Mossy Fiber Pathway of Cerebellum

Signal elaboration in the cerebellum mossy fiber input pathway presents controversial aspects, especially concerning gain regulation and the spot-like (rather than beam-like) appearance of granular to molecular layer transmission. By using voltage-sensitive dye imaging in rat cerebellar slices (Mapelli et al., 2010), we found that mossy fiber bursts optimally excited the granular layer above ∼50 Hz and the overlaying molecular layer above ∼100 Hz, thus generating a cascade of high-pass filters. NMDA receptors enhanced transmission in the granular, while GABA-A receptors depressed transmission in both the granular and molecular layer. Burst transmission gain was controlled through a dynamic frequency-dependent involvement of these receptors. Moreover, while high-frequency transmission was enhanced along vertical lines connecting the granular to molecular layer, no high-frequency enhancement was observed along the parallel fiber axis in the molecular layer. This was probably due to the stronger effect of Purkinje cell GABA-A receptor-mediated inhibition occurring along the parallel fibers than along the granule cell axon ascending branch. The consequent amplification of burst responses along vertical transmission lines could explain the spot-like activation of Purkinje cells observed following punctuate stimulation in vivo

Cognitive functioning, clinical profile and life events in young adults addicted to drugs. Does being a girl make a difference?

Objective: Gender features play a fundamental role as risk factors in drug addiction, entailing differences in vulnerability, onset, drug use and clinical trajectories. Even if increasing empirical evidence has attested that drug abuse in emerging adulthood is associated with cognitive impairments, personality disorders and psychological distress, limited research has analyzed these aspects from a gender perspective. The present research focuses on gender differences in youths (18–24 years of age) diagnosed with substance use disorders (SUDs), in order to detect possible differences between females and males as regards their neuropsychological functioning, clinical profiles and past life experiences. Method: Neuropsychological functioning (neuropsychological battery Esame Neuropsicologico Breve-2), the severity of the symptomatology (Symptom Checklist-90-Revised), personality profile and disorders (Shedler Westen Assessment Procedure-200) and life history were assessed in two groups of young adults with SUDs, 20 males and 20 females (mean age = 21 years, SD = 2.2). Participants were recruited in a therapeutic community in Venice, Italy. Results: Girls showed less cognitive impairment but higher psychological distress with respect to boys; between the two groups, no differences emerged regarding the personality profiles. The girls’ life histories presented more experiences of abuse and maltreatment; they also moved more quickly from substance use to dependence. Boys, instead, were more involved in criminal activity. Conclusions: Given our results, it seems that gender differences manifest early, at emerging adulthood. Consequently, a gender-oriented treatment for drug addiction should be offered even at an early age, focusing on early adverse experiences and their potential traumatic effect on girls. By contrast, young men seem to rely on compromised cognitive functions, which require a specific treatment approach, since they constitute a crucial factor for individual adjustment and treatment outcomes. Results should be interpreted relative to some limitations (such as the small sample size and the preliminary and cross-sectional nature of the research), and future studies are require

Neurodidattica: uno spazio dialogico tra saperi per innovare i processi di insegnamento e apprendimento

L\u2019articolo ha cercato di evidenziare due aspetti principali: la relazione tra alcune teorie sull\u2019apprendimento degli adulti, ovvero tra l\u2019apprendimento esperienziale, l\u2019apprendimento trasformativo e il brain based learning; le implicazioni di questa relazione per i metodi di insegnamento e apprendimento. La finalit\ue0 principale del lavoro proposto \ue8 stato quello di concentrarsi sulla dimensione olistica dell\u2019apprendimento degli adulti, verso il quale, accanto alle teorie tradizionali, stanno guadagnando attenzione altre dimensioni importanti come le emozioni, la spiritualit\ue0 e il corpo, ma anche la relazione tra il funzionamento del cervello e l\u2019apprendimento. Con il supporto della revisione della letteratura, lo studio ha esplorato quattro fattori importanti: a) la relazione tra le caratteristiche del nostro cervello e il processo di apprendimento; b) le relazioni tra emozioni e apprendimento; c) la relazione tra neuroscienze e alcune teorie dell\u2019apprendimento degli adulti; d) le implicazioni per le pratiche didattiche. Tutto ci\uf2 ha suggerito alcune importanti riflessioni sulla potenzialit\ue0 della neurodidattic

Inhibitory Plasticity: From Molecules to Computation and Beyond

Synaptic plasticity is the cellular and molecular counterpart of learning and memory and, since its first discovery, the analysis of the mechanisms underlying long-term changes of synaptic strength has been almost exclusively focused on excitatory connections. Conversely, inhibition was considered as a fixed controller of circuit excitability. Only recently, inhibitory networks were shown to be finely regulated by a wide number of mechanisms residing in their synaptic connections. Here, we review recent findings on the forms of inhibitory plasticity (IP) that have been discovered and characterized in different brain areas. In particular, we focus our attention on the molecular pathways involved in the induction and expression mechanisms leading to changes in synaptic efficacy, and we discuss, from the computational perspective, how IP can contribute to the emergence of functional properties of brain circuits

Cognitive reserve in dementia: Implications for cognitive training

open9noCognitive reserve (CR) is a potential mechanism to cope with brain damage. The aim of this study was to evaluate the effect of CR on a cognitive training (CT) in a group of patients with dementia. Eighty six participants with mild to moderate dementia were identified by their level of CR quantified by the CR Index questionnaire (CRIq) and underwent a cycle of CT. A global measure of cognition mini mental state examination (MMSE) was obtained before (T0) and after (T1) the training. Multiple linear regression analyses highlighted CR as a significant factor able to predict changes in cognitive performance after the CT. In particular, patients with lower CR benefited from a CT program more than those with high CR. These data show that CR can modulate the outcome of a CT program and that it should be considered as a predictive factor of neuropsychological rehabilitation training efficacy in people with dementia.openMondini, Sara; Madella, Ileana; Zangrossi, Andrea; Bigolin, Angela; Tomasi, Claudia; Michieletto, Marta; Villani, Daniele; Di Giovanni, Giuseppina; Mapelli, DanielaMondini, Sara; Madella, Ileana; Zangrossi, Andrea; Bigolin, Angela; Tomasi, Claudia; Michieletto, Marta; Villani, Daniele; Di Giovanni, Giuseppina; Mapelli, Daniel

Biologically Plausible Information Propagation in a CMOS Integrate-and-Fire Artificial Neuron Circuit with Memristive Synapses

Neuromorphic circuits based on spikes are currently envisioned as a viable option to achieve brain-like computation capabilities in specific electronic implementations while limiting power dissipation given their ability to mimic energy efficient bio-inspired mechanisms. While several network architectures have been developed to embed in hardware the bio-inspired learning rules found in the biological brain, such as the Spike Timing Dependent Plasticity, it is still unclear if hardware spiking neural network architectures can handle and transfer information akin to biological networks. In this work, we investigate the analogies between an artificial neuron combining memristor synapses and rate-based learning rule with biological neuron response in terms of information propagation from a theoretical perspective. Bio-inspired experiments have been reproduced by linking the biological probability of release with the artificial synapses conductance. Mutual information and surprise have been chosen as metrics to evidence how, for different values of synaptic weights, an artificial neuron allows to develop a reliable and biological resembling neural network in terms of information propagation and analysi

Expectancy to Eat Modulates Cognitive Control and Attention Toward Irrelevant Food and Non-food Images in Healthy Starving Individuals. A Behavioral Study

It is thought that just as hunger itself, the expectancy to eat impacts attention and cognitive control toward food stimuli, but this theory has not been extensively explored at a behavioral level. In order to study the effect of expectancy to eat on attentional and cognitive control mechanisms, 63 healthy fasting participants were presented with an affective priming spatial compatibility Simon task that included both food and object (non-food) distracters. The participants (N = 63) were randomly assigned to two groups: an “immediate expectancy” group made up of participants who expected to eat immediately after the task (N = 31; females = 21; age = 26.8 ± 9.6) and a “delayed expectancy” cohort made up of individuals who expected to eat a few hours later (N = 32; females = 21; age = 25.0 ± 8.0). Slower reaction times (RTs) toward the food and non-food distracters and a more pronounced effect on the RTs in the incompatible condition [i.e., the Simon effect (SE)] were noted in both groups. The effect of the food and non-food distracters on the RTs was more pronounced in the immediate with respect to the delayed expectancy group. The magnitude of the SE for the food and the non-food distracters was also greater in the immediate with respect to the delayed expectancy group. These results seem to indicate that when the expectancy to eat is short, the RTs are delayed, and the SE is more pronounced when food and non-food distracters are presented. Instead, when the expectancy to eat is more distant, the distracters have less of an effect on the RTs and the correspondence effect is smaller. Our results suggest that the expectancy to eat can modulate both attention orienting and cognitive control mechanisms in healthy fasting individuals when distracting details are competing with information processing during goal directed behavior

Scattering Compensation for Deep Brain Microscopy: The Long Road to Get Proper Images

Multiphoton microscopy is the most widespread method for preclinical brain imaging when sub-micrometer resolution is required. Nonetheless, even in the case of optimal experimental conditions, only a few hundred micrometers under the brain surface can be imaged by multiphoton microscopy. The main limitation preventing the acquisition of images from deep brain structures is the random light scattering which, until recently, was considered an unsurmountable obstacle. When in 2007 a breakthrough work by Vellekoop and Mosk [1] proved it is indeed possible to compensate for random scattering by using high resolution phase modulators, the neuro-photonics community started chasing the dream of a multiphoton microscopy capable of reaching arbitrary depths within the brain. Unfortunately, more than 10 years later, despite a massive improvement of technologies for scattering compensation in terms of speed, performances and reliability, clear images from deep layers of biological tissues are still lacking. In this work, we review recent technological and methodological advances in the field of multiphoton microscopy analyzing the big issue of scattering compensation. We will highlight the limits hampering image acquisition, and we will try to analyze the road scientists must tackle to target one of the most challenging issue in the field of biomedical imaging

Editorial: Brain-inspired computing: Neuroscience drives the development of new electronics and artificial intelligence

Editorial for a special issue (i.e. "Research Topic") launched on the Journal Frontiers in Cellular Neuroscience - Section Cellular Neurophysiology