Abstract In the mammalian neocortex, excitatory neurons provide excitation in both columnar and laminar dimensions, which is modulated further by inhibitory neurons. However, our understanding of intracortical excitatory and inhibitory synaptic inputs in relation to principal excitatory neurons remains incomplete, and it is unclear how local excitatory and inhibitory synaptic connections to excitatory neurons are spatially organized on a layer-by-layer basis. In the present study, we combined whole cell recordings with laser scanning photostimulation via glutamate uncaging to map excitatory and inhibitory synaptic inputs to single excitatory neurons throughout cortical layers 2/3–6 in the mouse primary visual cortex (V1). We find that synaptic input sources of excitatory neurons span the radial columns of laminar microcircuits, and excitatory neurons in different V1 laminae exhibit distinct patterns of layer-specific organizationofexcitatoryinputs.Remarkably,thespatialextentofinhibitoryinputsofexcitatory neurons for a given layer closely mirrors that of their excitatory input sources, indicating that excitatory and inhibitory synaptic connectivity is spatially balanced across excitatory neuronal networks. Strong interlaminar inhibitory inputs are found, particularly for excitatory neurons in layers 2/3 and 5. This differs from earlier studies reporting that inhibitory cortical connections to excitatory neurons are generally localized within the same cortical layer. On the basis of the functional mapping assays, we conducted a quantitative assessment of both excitatory and inhibitory synaptic laminar connections to excitatory cells at single cell resolution, establishing precise layer-by-layer synaptic wiring diagrams of excitatory neurons in the visual cortex.
Pten and eph b4 regulate the establishment of perisomatic inhibition in mouse...Taruna Ikrar
Perisomatic inhibition of pyramidal neurons is established by fast-spiking, parvalbuminexpressing interneurons (PV cells). Failure to assemble adequate perisomatic inhibition is thought to underlie the aetiology of neurological dysfunction in seizures, autism spectrum disorders and schizophrenia. Here we show that in mouse visual cortex, strong perisomatic inhibition does not develop if PV cells lack a single copy of Pten. PTEN signalling appears to drive the assembly of perisomatic inhibition in an experience-dependent manner by suppressing the expression of EphB4; PVcells hemizygous for Pten show an B2-fold increase in expression of EphB4, and over-expression of EphB4 in adult PV cells causes a dismantling of perisomatic inhibition. These findings implicate a molecular disinhibitory mechanism driving the establishment of perisomatic inhibition whereby visual experience enhances Pten signalling, resulting in the suppression of EphB4 expression; this relieves a native synaptic repulsion between PV cells and pyramidal neurons, thereby promoting the assembly of perisomatic inhibition.
Un presupuesto transparente y un ajuste fiscal aún pendientesFUSADES
El 30 de septiembre de 2016, se presentó el proyecto de
presupuesto 2017 (PP2017) a la Asamblea Legislativa, el cual
no solo presentaba los mismos vacíos de los presupuestos
aprobados en los últimos años, sino que, además, incorporaba
otras importantes distorsiones1
, por lo que debió haberse
reformado antes de su aprobación.
No había ningún impedimento jurídico para que el Órgano
Legislativo pidiera al Ejecutivo que corrigiera el proyecto ya
presentado2
. El período de análisis y discusión es precisamente
para hacer las modificaciones que lo mejoren. De hecho, cada
año, el proyecto de presupuesto se modifica; aunque, por lo
general, han sido cambios menores, ya que en los últimos años
los presupuestos aprobados no han sido realistas.
Abstract In the mammalian neocortex, excitatory neurons provide excitation in both columnar and laminar dimensions, which is modulated further by inhibitory neurons. However, our understanding of intracortical excitatory and inhibitory synaptic inputs in relation to principal excitatory neurons remains incomplete, and it is unclear how local excitatory and inhibitory synaptic connections to excitatory neurons are spatially organized on a layer-by-layer basis. In the present study, we combined whole cell recordings with laser scanning photostimulation via glutamate uncaging to map excitatory and inhibitory synaptic inputs to single excitatory neurons throughout cortical layers 2/3–6 in the mouse primary visual cortex (V1). We find that synaptic input sources of excitatory neurons span the radial columns of laminar microcircuits, and excitatory neurons in different V1 laminae exhibit distinct patterns of layer-specific organizationofexcitatoryinputs.Remarkably,thespatialextentofinhibitoryinputsofexcitatory neurons for a given layer closely mirrors that of their excitatory input sources, indicating that excitatory and inhibitory synaptic connectivity is spatially balanced across excitatory neuronal networks. Strong interlaminar inhibitory inputs are found, particularly for excitatory neurons in layers 2/3 and 5. This differs from earlier studies reporting that inhibitory cortical connections to excitatory neurons are generally localized within the same cortical layer. On the basis of the functional mapping assays, we conducted a quantitative assessment of both excitatory and inhibitory synaptic laminar connections to excitatory cells at single cell resolution, establishing precise layer-by-layer synaptic wiring diagrams of excitatory neurons in the visual cortex.
Pten and eph b4 regulate the establishment of perisomatic inhibition in mouse...Taruna Ikrar
Perisomatic inhibition of pyramidal neurons is established by fast-spiking, parvalbuminexpressing interneurons (PV cells). Failure to assemble adequate perisomatic inhibition is thought to underlie the aetiology of neurological dysfunction in seizures, autism spectrum disorders and schizophrenia. Here we show that in mouse visual cortex, strong perisomatic inhibition does not develop if PV cells lack a single copy of Pten. PTEN signalling appears to drive the assembly of perisomatic inhibition in an experience-dependent manner by suppressing the expression of EphB4; PVcells hemizygous for Pten show an B2-fold increase in expression of EphB4, and over-expression of EphB4 in adult PV cells causes a dismantling of perisomatic inhibition. These findings implicate a molecular disinhibitory mechanism driving the establishment of perisomatic inhibition whereby visual experience enhances Pten signalling, resulting in the suppression of EphB4 expression; this relieves a native synaptic repulsion between PV cells and pyramidal neurons, thereby promoting the assembly of perisomatic inhibition.
Un presupuesto transparente y un ajuste fiscal aún pendientesFUSADES
El 30 de septiembre de 2016, se presentó el proyecto de
presupuesto 2017 (PP2017) a la Asamblea Legislativa, el cual
no solo presentaba los mismos vacíos de los presupuestos
aprobados en los últimos años, sino que, además, incorporaba
otras importantes distorsiones1
, por lo que debió haberse
reformado antes de su aprobación.
No había ningún impedimento jurídico para que el Órgano
Legislativo pidiera al Ejecutivo que corrigiera el proyecto ya
presentado2
. El período de análisis y discusión es precisamente
para hacer las modificaciones que lo mejoren. De hecho, cada
año, el proyecto de presupuesto se modifica; aunque, por lo
general, han sido cambios menores, ya que en los últimos años
los presupuestos aprobados no han sido realistas.
2. Pri každej slovnej úlohe urob: zápis
výpočet
odpoveď
V jednom malom kráľovstve, kdesi za siedmimi horami
a siedmimi dolami žilo milé a usilovné dievčatko, ktoré všetci
volali Popoluška. Mamka mu zomrela a otec si zobral za
manželku zlú Izabelu s dvoma dcérami. Otec čoskoro
ochorel a zomrel. Popoluška zostala na svete sama,
pretože ju jej macocha, ani nevlastné sestry nemali
rady.
3. Izabela má vo svojom poklade 1 767 perál a drahokamov.
Svojim dcéram darovala 383 perál a 250 drahokamov.
Koľko perál a drahokamov jej zostalo?
4. Na kráľovskom zámku sa mal konať bál. Preto macocha a jej dcéry
potrebovali nové šaty. Spolu kúpili 936 m látky. Z toho na šaty použili
598 m brokátu, 362 m šifónu a 21 m saténu. Koľko
metrov látky im ešte zostalo.
5. Na ples prišlo spolu 13 965 hostí. Z toho 6 596 hostí bolo chlapcov
a 6 789 dievčat. Koľko dospelých bolo na plese?
6. Blaho elám k úspešnémuž
vyriešeniu úloh.
Popoluška
7. Blaho elám k úspešnémuž
vyriešeniu úloh.
Popoluška