Past events

Major failures in AD patients with several low molecular weight (LMW) compounds and certain immunotherapies indicate that the etiology of the disease is still elusive. Therefore future therapies should address all AD hallmarks, regardless of prime etiological culprits. In this lecture several low molecular weight (LMW) compounds and their respective target(s) are critically discussed as potential treatments for AD including, inter alia: cholinergic modulators [cholinesterase inhibitors (AChE-Is), alpha7-nicotinic agonists, M1 muscarinic agonists], alpha-secretase activators, BACE1 inhibitors, gamma-secretase inhibitors or modulators, inhibitors of beta-amyloids (Abeta) aggregation or Abeta-induced neurotoxicity, inhibitors of tau proteins hyperphosphorylation and/or tau proteins aggregation, GSK-3beta inhibitors and sigma-1 receptor (Sig1R) agonists. Comparison among these compounds is made when possible also with M1 muscarinic agonists and a new compound, AF710B. In this context the M1 muscarinic receptor (M1 mAChR) appears to be a pivotal target for treatment of AD, Parkinson's disease (PD) and Lewy body dementia (LBD). Notably the M1 muscarinic agonists AF102B, AF267B, AF292 are effective cognitive enhancers and disease modifiers with a wide safety margin. Thus - i) AF102B decreased CSF Abeta in AD patients (Nitsch et al, Ann Neurol 2000); ii) AF267B rescued cognitive deficits and decreased Abeta42 and tau pathologies in 3xTg-AD mice (Caccamo et al, Neuron, 2006); and iii) AF102B and AF267B decreased brain alpha-synuclein aggregates in transgenic mice overexpressing human alpha-synuclein (Fisher et al., ADPD 2011). However in spite of their potential in disease modification (DM) and cognitive enhancement, M1 agonists (either orthosteric or allosteric) still do not address a prime disease hallmark, e.g. mitochondrial dysfunctions, which can be ameliorated via the molecular chaperone Sig1R. In this context we have designed a novel molecule, AF710B (MW, 357.5) which shows a novel mechanism of action (MoA) of enhancing neuroprotection and cognition via Sig1R activation and M1 muscarinic allosteric modulation, but not resembling Sig1R, M1 muscarinic (allosteric or orthosteric) and dual Sig1R/M1 agonists, respectively. The effects of AF710B at low concentrations in vitro against neurodegeneration, oxidative stress, Abeta, Tau-phosphorylation and GSK-3beta activation translate into down-regulation of the apoptotic protein Bax and mitochondrial dysfunction, up-regulation of anti-apoptotic Bcl2. AF710B has an exceptional pharmacology being an excellent cognitive enhancer in rats (at 1-30 and 10-100mcg/kg, po in trihexyphenidyl- and in MK801-induced passive avoidance impairments, respectively). AF710B is devoid of side effects, having an unprecedented safety margin > 50,000 (po). Furthermore, AF710B mitigated cognitive impairments, reduced Abeta40, Abeta42 levels and tau pathology and inflammation in 3xTg-AD mice AF710B (at 10 mcg/kg, ip/daily for 2 months; Morris water maze). The unique effects of AF710B can be explained by a super-sensitization of M1 mAChR through a hypothetical heteromerization with Sig1R. Conclusions: Only some of the reviewed compounds can bridge treatment of both cognitive impairments with DM. In this context, AF710B is the 1st reported low MW CNS-penetrable mono-therapy that meets comprehensively this challenge. The unmatched potency of AF710B on cognition and on amyloid and tau pathologies, combined with its beneficial effects on inflammation and mitochondrial dysfunctions, indicates extensive therapeutic advantages for AF710B in AD and other protein-aggregation related diseases vs. a plethora of experimental and licensed treatments. Keywords: M1 muscarinic receptor, M1 agonist, disease modifiers, beta-amyloids, sigma-1 agonist, tau proteins, alpha-synuclein

Throughout the history of neuroscience, from the Chinese to the Egyptians and Romans, it was a key problem to find the seat of human experience. Once it was discovered that the brain is the sole proprietor of the human mind, a second flurry of scientific discourse focused on defining the localization of cognitive functions in the vast mantle of the brain. In my talk, after a brief historical overview, I will discuss the notion of localization of function in the brain in light of recent data from intracranial electrophysiological recordings during real life settings and electrical stimulation of the brain in conscious human subjects.

Empathy, the recognition and sharing of affective states between individuals, is an adaptive response with ancient evolutionary roots. The experience of empathy rises from activation of subcortical neural circuits in the brain stem, thalamus and paralimbic areas that are highly conserved across mammalian species. Primarily, it is crucial for the survival of altricial mammals to be able to respond to the needs of offspring appropriately. More broadly, communication of emotions promotes group survival, by alerting against potential threats and, depending on context, inducing pro-social actions. Behavioral homologues of empathy have been observed in different non-human animals. For instance, it has been clearly established that rodents display emotional contagion of others’ distress, and are motivated to alleviate another rat’s distress. We found that rats intentionally released a cagemate trapped in a restrainer, even when social contact was prevented. When a second restrainer containing a highly palatable food (chocolate chips) was present, rats opened both restrainers and typically shared the chocolate. Since only cagemates were tested, it is unclear if these behaviors generalize to strangers. Helping others is costly and resource depleting, and should thus be discriminately extended. In humans, the expression of empathically motivated pro-social behavior is dependent on social context, where people are more motivated to help in-group members than out-group members. Correspondingly, emotional contagion is modulated by familiarity in rodents. Mice have been found to display heightened pain sensitivity when witnessing a cagemate in pain, but not a stranger in pain. To investigate these questions, we are currently exploring the effect of social parameters such as familiarity and relatedness on the expression of empathic helping in rats.

Understanding human brain structure and function organization in health, disease and development is one of the great challenges for neuroscience. Magnetic resonance imaging (MRI) is the most valuable technique for noninvasive in vivo imaging of human brain. However, the use of MRI is currently limited, due to the lack of theory that links the specific biological structures to the measured signal. In my presentation I will describe a new quantitative MRI (qMRI) method that directly measures two biophysical properties of the human brain tissue: the macromolecular tissue volume and the macromolecular physico-chemical environment. I will discuss how such quantities can be used for 1) individualize diagnostic applications and 2) mapping structure-function relations in cognitive processes such as reading.