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98. Differential effects of emotional motivational stimuli on specifically stimulated hippocampal neurons in vivo
Society Proceedings / Clinical Neurophysiology 119 (2008) e99–e164
ities were comparatively more severe for R–G than for luminance stimuli. In IPD all responses were abnormal, above all for B–Y stimuli, whereas they were spared in MSA. The above findings indicate that ChPERGs, may be reliably recorded in normal observers as well as in pt. by means of skin electrodes. The stimulus-dependent response abnormalities suggest a differential retinal impairment in some neurological disorders. doi:10.1016/j.clinph.2008.04.110
95. Pattern visual evoked potentials (PVEP) in successfully treated amblyopic children impaired—M.S. Roy, M.L. Be´lair, J.L. Jacob, J. Hotte-Bernard, D. St-Amour (Canada) The aim of this study was to assess, using PVEP, the functional integrity of visual cortex after a successful clinical treatment of amblyopia. Eighteen successfully treated amblyopic children and 19 controls were tested. PVEP were recorded in response to stimuli defined by two standard spatial frequencies (0,5 and 2,5 c/deg) and 4 contrast levels (4,12,28 and 95%. The results show a delay of the N75 at 4% contrast, a small delay of the P100 component and a lower amplitude of the P100 component in the treated amblyopic eye compared to the non amblyopic eye. Our finding observed at 4% contrast level suggests a preferential alteration of the magnocellular system. Furthermore, the residual deficit is likely to involve extra-striate areas because of the origin of P1 generators. This study suggests that a successful clinical treatment does not necessary imply a complete recovery of visual function. doi:10.1016/j.clinph.2008.04.111
96. Early detection of Alzheimer disease: Electrophysiological markers based on the n400 component of the evoked related potential—A. Ferna´ndez Nin, Y. Ferna´ndez, M.A. Bobes Leo´n, F. Lopera, Y.T. Quiroz, Z. Ortiz, L. Leyva Medrano, M. Feria (Cuba) The diagnosis of AD depends basically on clinical criteria which exclude early diagnosis. It is important to find biological markers at early stages of Alzheimer Disease (AD) to guarantee the best possible care to the patient by taken advantages of this therapeutic window. Subjects with Mild Cognitive Impairment (MCI) constitute a population at risk of developing the AD. Moreover, they are a large number of subjects in the population over 65 years old and not all of them evolve to an AD. For these reasons they are restricted as a target population for therapeutic interventions. This work proposes to study electrophysiological markers based on the N400 component of the Evoked Related Potential (ERP) in early stages of Alzheimer’s disease (AD). Two populations were tested, families with the E260A presinilin-1 mutation and amnestic mild cognitive impairment (amci) subjects. In both ERP were recording during a semantic task to study the N400 component. Topography and inverse solution analysis (ISA) were carried out. The results show that morphological and functional changes take place in both groups preceding the onset
e123
of the clinical symptoms, and these changes can be detected by tomographic methods. doi:10.1016/j.clinph.2008.04.112
97. Sleep disorders in Parkinson’s disease—I. Pedroso ´ lvarez Gonza´lez, M. Iban˜ez, M.L. Bringas Vega, L. A ´ lvarez Sa´nchez, A. Padro´n Sa´nchez, A. Dıaz de la Fe´ A (Cuba) Sleep disorders occur before the onset of clinical manifestations of PD. These disorders are reported in 60–98% PD patients and are dependent on many factors. We performed surveys on sleep characteristics even when there were no spontaneous complaints in a sample of 50 patients with PD, hospitalized at CIREN’s Clinic of Movement Disorders and thus, define the management to follow. These data were analysed according to age groups, clinical stages and predominance of symptoms, clinical complications, anti-parkinsonian and anti-depressive medication and hypnotics used. Secondary insomnia was due to various causes in: 72% of them the presence of parkinsonian symptoms during the night constituted the predominant symptom. Daytime somnolence was observed in 65% of the sample. Nightmares and nocturnal terrors followed (46%) These symptoms were present in all the stages of the disease, increasing in relation to age, clinical stage, motor complications and some antiparkinsonian medications. All the patients required specific treatment for the sleep disorders. doi:10.1016/j.clinph.2008.04.113
98. Differential effects of emotional motivational stimuli on specifically stimulated hippocampal neurons in vivo—W. Almaguer, J. Lo´pez-Rojas, J.U. Frey, J. Bergado Rosado (Cuba) Hippocampal long-term potentiation (LTP) is a long-lasting increase in synaptic efficacy considered to be relevant for learning and memory. LTP is characterized by an early phase depending on post-translational protein modification (E-LTP, < 4 h) and a late phase that depends on protein synthesis (L-LTP, > 4 h). In the behaving, water-deprived rat E-LTP can be reinforced into a L-LTP, if the rats were allowed to drink within 15 min after E-LTP induction (‘‘behavioral LTP-reinforcement”, BR). Processes of ‘‘synaptic tagging” can explain BR. This hypothesis supposes that the tetanization induces a transient E-LTP and sets a tag at the activated synapses, that are then able to capture and to process plasticity-related proteins (PRPs) required for L-LTP. PRPs can be synthesized via heterosynaptic interactions, activated by the BR, when these take place in a time window of about 30 min before or after E-LTP induction. LTP can be reversed by low-frequency stimulation (LFS; i.e. depotentiation) to the same synaptic input if applied shortly after tetatization (< 10 min). Here we address the question of whether a BR protocol is able to recover LTP at depotentiated synapses, which probably involve the preservation of synaptic tags. doi:10.1016/j.clinph.2008.04.114
ities were comparatively more severe for R–G than for luminance stimuli. In IPD all responses were abnormal, above all for B–Y stimuli, whereas they were spared in MSA. The above findings indicate that ChPERGs, may be reliably recorded in normal observers as well as in pt. by means of skin electrodes. The stimulus-dependent response abnormalities suggest a differential retinal impairment in some neurological disorders. doi:10.1016/j.clinph.2008.04.110
95. Pattern visual evoked potentials (PVEP) in successfully treated amblyopic children impaired—M.S. Roy, M.L. Be´lair, J.L. Jacob, J. Hotte-Bernard, D. St-Amour (Canada) The aim of this study was to assess, using PVEP, the functional integrity of visual cortex after a successful clinical treatment of amblyopia. Eighteen successfully treated amblyopic children and 19 controls were tested. PVEP were recorded in response to stimuli defined by two standard spatial frequencies (0,5 and 2,5 c/deg) and 4 contrast levels (4,12,28 and 95%. The results show a delay of the N75 at 4% contrast, a small delay of the P100 component and a lower amplitude of the P100 component in the treated amblyopic eye compared to the non amblyopic eye. Our finding observed at 4% contrast level suggests a preferential alteration of the magnocellular system. Furthermore, the residual deficit is likely to involve extra-striate areas because of the origin of P1 generators. This study suggests that a successful clinical treatment does not necessary imply a complete recovery of visual function. doi:10.1016/j.clinph.2008.04.111
96. Early detection of Alzheimer disease: Electrophysiological markers based on the n400 component of the evoked related potential—A. Ferna´ndez Nin, Y. Ferna´ndez, M.A. Bobes Leo´n, F. Lopera, Y.T. Quiroz, Z. Ortiz, L. Leyva Medrano, M. Feria (Cuba) The diagnosis of AD depends basically on clinical criteria which exclude early diagnosis. It is important to find biological markers at early stages of Alzheimer Disease (AD) to guarantee the best possible care to the patient by taken advantages of this therapeutic window. Subjects with Mild Cognitive Impairment (MCI) constitute a population at risk of developing the AD. Moreover, they are a large number of subjects in the population over 65 years old and not all of them evolve to an AD. For these reasons they are restricted as a target population for therapeutic interventions. This work proposes to study electrophysiological markers based on the N400 component of the Evoked Related Potential (ERP) in early stages of Alzheimer’s disease (AD). Two populations were tested, families with the E260A presinilin-1 mutation and amnestic mild cognitive impairment (amci) subjects. In both ERP were recording during a semantic task to study the N400 component. Topography and inverse solution analysis (ISA) were carried out. The results show that morphological and functional changes take place in both groups preceding the onset
e123
of the clinical symptoms, and these changes can be detected by tomographic methods. doi:10.1016/j.clinph.2008.04.112
97. Sleep disorders in Parkinson’s disease—I. Pedroso ´ lvarez Gonza´lez, M. Iban˜ez, M.L. Bringas Vega, L. A ´ lvarez Sa´nchez, A. Padro´n Sa´nchez, A. Dıaz de la Fe´ A (Cuba) Sleep disorders occur before the onset of clinical manifestations of PD. These disorders are reported in 60–98% PD patients and are dependent on many factors. We performed surveys on sleep characteristics even when there were no spontaneous complaints in a sample of 50 patients with PD, hospitalized at CIREN’s Clinic of Movement Disorders and thus, define the management to follow. These data were analysed according to age groups, clinical stages and predominance of symptoms, clinical complications, anti-parkinsonian and anti-depressive medication and hypnotics used. Secondary insomnia was due to various causes in: 72% of them the presence of parkinsonian symptoms during the night constituted the predominant symptom. Daytime somnolence was observed in 65% of the sample. Nightmares and nocturnal terrors followed (46%) These symptoms were present in all the stages of the disease, increasing in relation to age, clinical stage, motor complications and some antiparkinsonian medications. All the patients required specific treatment for the sleep disorders. doi:10.1016/j.clinph.2008.04.113
98. Differential effects of emotional motivational stimuli on specifically stimulated hippocampal neurons in vivo—W. Almaguer, J. Lo´pez-Rojas, J.U. Frey, J. Bergado Rosado (Cuba) Hippocampal long-term potentiation (LTP) is a long-lasting increase in synaptic efficacy considered to be relevant for learning and memory. LTP is characterized by an early phase depending on post-translational protein modification (E-LTP, < 4 h) and a late phase that depends on protein synthesis (L-LTP, > 4 h). In the behaving, water-deprived rat E-LTP can be reinforced into a L-LTP, if the rats were allowed to drink within 15 min after E-LTP induction (‘‘behavioral LTP-reinforcement”, BR). Processes of ‘‘synaptic tagging” can explain BR. This hypothesis supposes that the tetanization induces a transient E-LTP and sets a tag at the activated synapses, that are then able to capture and to process plasticity-related proteins (PRPs) required for L-LTP. PRPs can be synthesized via heterosynaptic interactions, activated by the BR, when these take place in a time window of about 30 min before or after E-LTP induction. LTP can be reversed by low-frequency stimulation (LFS; i.e. depotentiation) to the same synaptic input if applied shortly after tetatization (< 10 min). Here we address the question of whether a BR protocol is able to recover LTP at depotentiated synapses, which probably involve the preservation of synaptic tags. doi:10.1016/j.clinph.2008.04.114