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<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">Les recuerdo el próximo lunes es el simposio sobre circuitos neuronales. No es necesario inscribirse, pueden venir directamente.<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">Sin duda va a estar muy bueno.<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">Les mando el cronograma y los abstracts de las charlas.
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">Por favor difundir!<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">Antonia
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt"> <strong><b><font face="Times New Roman">Simposio sobre Circuitos Neuronales</font></b></strong><o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">21 de Noviembre 2011 de 9:30-13 hs<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">Auditorio Fundación Instituto Leloir<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">Av. Patricias Argentinas 435
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:
12.0pt">9:30
<strong><b><font face="Times New Roman">Gabriel Mindlin</font></b></strong>, Departamento de Física, FCEN, UBA<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt">Neurons tuning to a synthetic birdsong
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt">10:30
<strong><b><font face="Times New Roman">Juan Goutman</font></b></strong>, INGEBI, CONICETFacilitation and depression determine timing of synaptic responses atthe Inner Hair Cell ribbon synapse
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt">11:00 Coffee Break
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt">11:30
<strong><b><font face="Times New Roman">Francisco Urbano</font></b></strong>, IFIBYNE, UBA-CONICET<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt">T-type calcium channels play a key role in GABAergic thalamocortical alterations mediated by cocaine administration
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt">12:00
<strong><b><font face="Times New Roman">Massimo Scanziani</font></b></strong>, Section of Neurobiology, University of
<st1:State w:st="on">California</st1:State> <st1:place w:st="on"><st1:City w:st="on">San Diego</st1:City>,
<st1:country-region w:st="on">USA</st1:country-region></st1:place><o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt">Addressing cortical processing by perturbing the activity of individual layers<br clear="all">
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><strong><b><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt">ABSTRACS</span></font></b></strong><span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><b><i><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold;font-style:italic">Gabriel Mindlin
<o:p></o:p></span></font></i></b></p>
<p class="MsoNormal"><b><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold">Neurons tuning to a synthetic birdsong<o:p></o:p></span></font></b></p>
<p class="MsoNormal"><font size="3" face="Arial"><span lang="EN-US" style="font-size:
12.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial">Abstract: Song birds, like humans, use learned signals to communicate. These are acquired from tutors during a specific time window by a process
that includes vocal imitation. It is natural then to choose birdsong as a suitable animal model for the study of learned complex behavior, and it is also reasonable that much of the study of vocal behavior has focused on its neural control. Yet, behavior emerges
from the interaction between a nervous system, a peripheral set of devices and environment, and therefore it is pertinent to study the interplay between central mechanisms of motor control and the peripheral systems. These interactions are particularly important
in birdsong, where neural instructions drive a highly nonlinear physical system. On the other hand, are the simplifications usual in physics and nonlinear dynamics capable of leading towards biologically pertinent synthetic outputs? In order to address this
issue, we compare the neural responses of a bird to both synthetic and natural songs. Neurons in the birdsong system exhibit strong selective responses to acoustic broadcast of the bird's own song (BOS), exhibiting stronger responses to BOS than tones, noises,
and even conspecific songs or slightly modified BOS. These responses have been intensively studied as a window into, and part of the mechanism of, sensorimotor vocal learning. BOS responses are strongest in sleeping birds, emerge early in sensorimotor learning,
and their prevalence may vary with species-specific patterns of learning. Despite their potential importance, the extreme response selectivity of song system neurons have made them difficult to study with traditional sensory physiological approaches. I will
present a line of work in which a low dimensional model for zebra finch song production was used to generate synthetic outputs. The model includes a description of the sound source and vocal tract where some mathematical parameters can be linked to physiological
properties observed during singing. We propose the hypothesis that changes in parameters in the model correspond to changes in motor control parameters birds actually use to control song output. To date we have seen that complete models elicit neuronal responses
in the HVC (a sensorimotor nucleus) strikingly similar to BOS responses, eliciting the same phasic-tonic features and somewhat lower magnitude of response. Progressively including the oropharyngeal cavity into the model, by changing its dissipation, allowing
it to progressively include its filtering influence into the sound, or increasing the intrinsic noise in the activity of the syringeal muscles results in systematic increase of response magnitude but not a change in phasic/tonic activity patterns. These results
demonstrate that a low dimensional model representing an approximation of peripheral mechanics is sufficient to capture behaviorally relevant features of song.
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial">This work has been done in collaboration with Ana Amador, Dan Margoliash and Yonatan Sanz Perl.<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><b><i><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold;font-style:italic">Juan Goutman<o:p></o:p></span></font></i></b></p>
<p class="MsoNormal"><b><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold">Facilitation and depression determine timing of synaptic responses at the Inner Hair Cell ribbon synapse<o:p></o:p></span></font></b></p>
<p class="MsoNormal"><b><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold"><o:p> </o:p></span></font></b></p>
<p class="MsoNormal" style="text-align:justify"><span class="apple-style-span"><font size="3" color="black" face="Times New Roman"><span lang="EN-US" style="font-size:
12.0pt;color:black">Abstract: The auditory system analyzes time and intensity to code location
of a sound source. These parameters are preferentially processed in different brainstem nuclei and so must be independently detected in the periphery and transmitted to the brain. In the first synapse of the hearing pathway, between inner hair cells and boutons
of auditory nerve neurons, analog signals are converted into a pattern of action potentials.
</span></font></span><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">By performing simultaneous pre- and post-synaptic recordings at this synapse, we investigated how the temporal structure and intensity of a stimulus
are encoded. Cyclic stimuli such as trains of depolarizations to different potentials, were presynaptically applied, trying to mimic acoustic stimuli of different intensities. Synaptic responses elicited by these trains presented constant first latencies (or
phase) within each cycle, even comparing different levels of depolarizations. In contrast, in single depolarizations, synaptic responses proved to have a voltage-(Ca<sup>2+</sup>-) dependence on timing. Interestingly, short-term facilitation partially compensated
for changes in latencies (and also reducing jitter) in these single pulses. We also showed that synaptic depression delayed release, offsetting any remaining differences in timing caused by different synaptic drives. Finally, we propose that an equilibrium
would be established between each stimuli level and the degree of synaptic depression, determining that in trains of stimuli the average phase was conserved.<o:p></o:p></span></font></p>
<p class="MsoNormal"><b><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold"><o:p> </o:p></span></font></b></p>
<p class="MsoNormal"><b><i><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold;font-style:italic">Francisco Urbano<o:p></o:p></span></font></i></b></p>
<p class="MsoNormal"><b><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold">T-type calcium channels play a key role in GABAergic thalamocortical alterations mediated by cocaine administration<o:p></o:p></span></font></b></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial">Abstract: Acute cocaine exposure has been shown to induce locomotor activity and GABAergic thalamic alterations. After systemic (i.p.) pre-administration
of either T-type calcium channel blockers mibefradil (20 mg/kg) or 2-octanol (0.5 mg/kg and 0.07 mg/kg) significantly prevented cocaine-induced hyperlocomotor activity in vivo as well as GABAergic mini frequencies onto VB neurons. Thus, strongly suggesting
that T-type calcium channels play a key role in cocaine-mediated GABAergic thalamocortical alterations, and further propose T-type channel blockers as potential targets for future pharmacological strategies aimed at treating cocaine’s deleterious effects on
physiology and behavior<o:p></o:p></span></font></p>
<p class="MsoNormal"><b><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold"><o:p> </o:p></span></font></b></p>
<p class="MsoNormal"><b><i><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold;font-style:italic">Massimo Scanziani<o:p></o:p></span></font></i></b></p>
<p class="MsoNormal"><b><font size="3" face="Arial"><span lang="EN-US" style="font-size:12.0pt;font-family:Arial;font-weight:bold">Addressing cortical processing by perturbing the activity of individual layers</span></font></b><font face="Arial"><span lang="EN-US" style="font-family:Arial"><o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial">Abstract: The cortex of the brain is responsible for sensations, thoughts, and other cognitive functions. It is composed of six layers of microcircuits
stacked on top of each other but we know little about the function of these layers in the processing of sensory information. Using a combination of optogenetic approaches and transgenic mouse-lines my lab is systematically addressing how each of these layers
contributes to the response of the cortex to sensory stimuli. I will present data showing that layer
<u1:metricconverter u2:st="on" ProductID="6 in"><st1:metricconverter ProductID="6 in" w:st="on">6 in</u1:metricconverter></st1:metricconverter> visual cortex performs a fundamental computation known as gain control. Through gain control layer 6 can act as a
volume knob to increase or decrease sensory evoked neuronal activity in all other layers. Because layer 6 receives convergent inputs from several brain areas, it may represent a node through which these various areas regulate the earliest steps of cortical
visual processing. <o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><font size="3" face="Times New Roman"><span lang="EN-US" style="font-size:12.0pt"><br>
</span>-- <br>
Antonia Marin Burgin, PhD<br>
Fundacion Instituto Leloir<br>
Av. Patricias Argentinas 435<br>
Buenos Aires 1405<br>
Argentina<br>
Phone (5411) 5238 7500 int 2307<br>
Fax (5411) 5238 7501<o:p></o:p></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt;
font-family:Arial"><o:p> </o:p></span></font></p>
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