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Suppressing actions is essential for flexible behavior. Multiple neural circuits involved in behavioral inhibition converge upon a key basal ganglia output nucleus, the substantia nigra pars reticulata (SNr). To examine how changes in basal ganglia output contribute to self-restraint, we recorded SNr neurons during a proactive behavioral inhibition task. Rats responded to Go! cues with rapid leftward or rightward movements, but also prepared to cancel one of these movement directions on trials when a Stop! cue might occur. This action restraint – visible as direction-selective slowing of reaction times – altered both rates and patterns of SNr spiking. Overall firing rate was elevated before the Go! cue, and this effect was driven by a subpopulation of direction-selective SNr neurons. In neural state space, this corresponded to a shift away from the restrained movement. SNr neurons also showed more variable inter-spike intervals during proactive inhibition. This corresponded to more variable state-space trajectories, which may slow reaction times via reduced preparation to move. These findings open new perspectives on how basal ganglia dynamics contribute to movement preparation and cognitive control.

In this paper was analyzed number of kernels per spike in 20 genetically divergent wheat cultivars originated from different breeding centers in Serbia. Investigation conducted during two seasons which characterized different climatic condition. For analysis used samples of 60 wheat plants (20 plants in 3 replications) which were harvested in full maturity stage. The differences in average values for number of kernels per spike in studied cultivars were determined. The variability of number of kernels per spike was established. In average, number of kernels per spike for all cultivars was higher in second year 72.22 than in first experimental year 68.73. The highest number of kernels/spike in both year expressed Tanjugovka cultivar and the lowest Yugoslavia cultivar. Average value of coefficientvariation for all cultivars varied from 14.19 in first year to 12.92 in second year. Average number of kernels per spike for both year of growing, varied from 54.56 in cultivar Yugoslavia to 77.83 in cultivar Tanjugovka. Significant differences for number of kernels/spike were found among cultivars in both years as well between years. Heritability in wide sense for number of kernels/spike was 79.13%.