Evolution of cortical neurons supporting human cognition.

Human cognitive abilities are generally thought to arise from cortical expansion over the course of human brain evolution. In addition to increased neuron numbers, this cortical expansion might be driven by adaptations in the properties of single neurons and their local circuits. We review recent findings on the distinct structural, functional, and transcriptomic features of human cortical neurons and their organization in cortical microstructure. We focus on the supragranular cortical layers, which showed the most prominent expansion during human brain evolution, and the properties of their principal cells: pyramidal neurons. We argue that the evolutionary adaptations in neuronal features that accompany the expansion of the human cortex partially underlie interindividual variability in human cognitive abilities.

Verbal and General IQ Associate with Supragranular Layer Thickness and Cell Properties of the Left Temporal Cortex.

The left temporal lobe is an integral part of the language system and its cortical structure and function associate with general intelligence. However, whether cortical laminar architecture and cellular properties of this brain area relate to verbal intelligence is unknown. Here, we addressed this using histological analysis and cellular recordings of neurosurgically resected temporal cortex in combination with presurgical IQ scores. We find that subjects with higher general and verbal IQ scores have thicker left (but not right) temporal cortex (Brodmann area 21, BA21). The increased thickness is due to the selective increase in layers 2 and 3 thickness, accompanied by lower neuron densities, and larger dendrites and cell body size of pyramidal neurons in these layers. Furthermore, these neurons sustain faster action potential kinetics, which improves information processing. Our results indicate that verbal mental ability associates with selective adaptations of supragranular layers and their cellular micro-architecture and function in left, but not right temporal cortex.

Safety and feasibility of prehospital thrombolysis in combination with active rescue PCI strategy for acute ST-elevation myocardial infarction.

BACKGROUND/OBJECTIVES: The purpose of this observational study was to provide an impression of the outcomes of prehospital thrombolysis in combination with an active coronary angioplasty intervention (PCI) strategy for acute ST-elevation myocardial infarction. METHODS: In a group of 151 consecutive patients the following parameters were measured: time delay, percentage of reperfusion, reocclusion, stroke, death, need for PCI and the number of protocol violations. RESULTS: The diagnosis by the ambulance paramedics was made in 8±6 minutes, followed by thrombolysis in 13±7 minutes (median±SD). In 2% (3) of the patients the thrombolytic agent was erroneously administered without complications. The elapsed time from onset of symptoms to treatment was a median of 112±77 minutes. Five percent (7) of the patients died in the first 30 days and 2% (3) suffered an intracerebral haemorrhage. Reperfusion was documented in 76% (112) of the patients, from which 18% (20) reoccluded in the following 24 hours. In patients where reperfusion was not established or reocclusion occurred, patients underwent rescue/facilitated PCI: in total 37% (55 patients). After three months 9% (13) of the patients had severly impaired (EF <40%) left ventricular function. CONCLUSION: In our region, we successfully implemented the prehospital thrombolysis system achieving a competitive call-to-needle time and reperfusion rate. The percentage of patients who violated the protocol, suffered an intracerebral haemorrhage, died and/or had severely impaired left ventricular function was acceptable.