Pathological cell assembly dynamics in a striatal MSN network model.

Under normal conditions the principal cells of the striatum, medium spiny neurons (MSNs), show structured cell assembly activity patterns which alternate sequentially over exceedingly long timescales of many minutes. It is important to understand this activity since it is characteristically disrupted in multiple pathologies, such as Parkinson's disease and dyskinesia, and thought to be caused by alterations in the MSN to MSN lateral inhibitory connections and in the strength and distribution of cortical excitation to MSNs. To understand how these long timescales arise we extended a previous network model of MSN cells to include synapses with short-term plasticity, with parameters taken from a recent detailed striatal connectome study.

Paradoxical Boosting of Weak and Strong Spatial Memories by Hippocampal Dopamine Uncaging.

The ability to remember changes in the surroundings is fundamental for daily life. It has been proposed that novel events producing dopamine release in the hippocampal CA1 region could modulate spatial memory formation. However, the role of hippocampal dopamine increase on weak or strong spatial memories remains unclear.

Noninvasive Monitoring of Blood Pressure and Heart Rate during Estrous Cycle Phases in Normotensive Wistar-Kyoto and Spontaneously Hypertensive Female Rats.

Since 2015, the National Institutes of Health has called for its funded preclinical research to include both male and female subjects. However, much of the basic animal research that has studied heart rate and blood pressure in the past has used male rats. Male rats have been preferred for these studies to avoid the possible complicating effects of the female estrous cycle.

Dopamine D and Adenosine A Receptors Interaction on Ca Current Modulation in a Rodent Model of Parkinsonism.

A receptor required previous D receptor activation to modulate Ca currents. Istradefylline decreases pramipexole modulation on Ca currents. Istradefylline reduces A + neurons activity in striatial microcircuit, but pramipexole failed to further reduce neuronal activity.

Conceptual framework for neuronal ensemble identification and manipulation related to behavior using calcium imaging.

The identification and manipulation of spatially identified neuronal ensembles with optical methods have been recently used to prove the causal link between neuronal ensemble activity and learned behaviors. However, the standardization of a conceptual framework to identify and manipulate neuronal ensembles from calcium imaging recordings is still lacking. We propose a conceptual framework for the identification and manipulation of neuronal ensembles using simultaneous calcium imaging and two-photon optogenetics in behaving mice.

Striatal Neuronal Ensembles Reveal Differential Actions of Amantadine and Clozapine to Ameliorate Mice L-DOPA-Induced Dyskinesia.

Amantadine and clozapine have proved to reduce abnormal involuntary movements (AIMs) in preclinical and clinical studies of L-DOPA-Induced Dyskinesias (LID). Even though both drugs decrease AIMs, they may have different action mechanisms by using different receptors and signaling profiles. Here we asked whether there are differences in how they modulate neuronal activity of multiple striatal neurons within the striatal microcircuit at histological level during the dose-peak of L-DOPA in ex-vivo brain slices obtained from dyskinetic mice.

Cortical stimulation relieves parkinsonian pathological activity in vitro.

Previously, we have shown that chemical excitatory drives such as N-methyl-d-aspartate (NMDA) are capable of activating the striatal microcircuit exhibiting neuronal ensembles that alternate their activity producing temporal sequences. One aim of this work was to demonstrate whether similar activity could be evoked by delivering cortical stimulation. Dynamic calcium imaging allowed us to follow the activity of dozens of neurons with single-cell resolution in mus musculus brain slices.