Journal of neuroscience methods
-
J. Neurosci. Methods · Jan 2012
Brain oxygen tension monitoring following penetrating ballistic-like brain injury in rats.
While brain oxygen tension (PbtO(2)) monitoring is an important parameter for evaluating injury severity and therapeutic efficiency in severe traumatic brain injury (TBI) patients, many factors affect the monitoring. The goal of this study was to identify the effects of FiO(2) (fraction of inspired oxygen) on PbtO(2) in uninjured anesthetized rats and measure the changes in PbtO(2) following penetrating ballistic-like brain injury (PBBI). Continuous PbtO(2) monitoring in uninjured anesthetized rats showed that PbtO(2) response was positively correlated with FiO(2) (0.21-0.35) but PbtO(2) remained stable when FiO(2) was maintained at ∼0.26. ⋯ In PBBI rats, PbtO(2) was significantly reduced by ∼40% (16.9 ± 1.2 mm Hg) in the peri-lesional region immediately following unilateral, frontal 10% PBBI compared to sham rats (28.6 ± 1.7 mm Hg; mean ± SEM, p<0.05) and the PBBI-induced reductions in PbtO(2) were sustained for at least 150 min post-PBBI. Collectively, these results demonstrate that FiO(2) affects PbtO(2) and that PBBI produces acute and sustained hypoxia in the peri-lesional region of the brain injury. This study provides important information for the management of PbtO(2) monitoring in this brain injury model and may offer insight for therapeutic strategies targeted to improve the hypoxia/ischemia state in the penetrating-type brain injury.
-
J. Neurosci. Methods · Jan 2012
Plate reader-based assays for measuring cell viability, neuroprotection and calcium in primary neuronal cultures.
Drug discovery and development efforts critically rely on cell-based assays for high-throughput screening. These assay systems mostly utilize immortalized cell lines, such as human embryonic kidney cells, and can provide information on cytotoxicity and cell viability, permeability and uptake of compounds as well as receptor pharmacology. While this approach has proven extremely useful for single-target pharmacology, there is an urgent need for neuropharmacological studies to screen novel drug candidates in a cellular environment resembles neurons in vivo more closely, in order to gain insight into the involvement of multiple signaling pathways. ⋯ We here developed and optimized protocols for the use of primary cortical neuronal cells in high-throughput assays for neuropharmacology and neuroprotection, including calcium mobilization, cytotoxicity and viability as well as ion channel pharmacology. Our data show low inter-experimental variability and similar reproducibility as conventional cell line assays. We conclude that primary neuronal cultures provide a viable alternative to cell lines in high-throughput assay systems by providing a cellular environment more closely resembling physiological conditions in the central nervous system.
-
J. Neurosci. Methods · Oct 2011
Clinical TrialModified flow- and oxygen-related autoregulation indices for continuous monitoring of cerebral autoregulation.
Continuous monitoring of brain tissue partial pressure of oxygen (ptiO(2)), thermal-diffusion regional cerebral blood flow (TD-rCBF) and cerebral perfusion pressure (CPP) allows the calculation of flow- and oxygen-related autoregulation indices ORx and FRx. The influence of temporal phase shifts on ORx and FRx due to a delay in the response time of ptiO(2) and TD-rCBF has received little attention. We investigated the impact of phase shifts between changes in CPP and the corresponding ptiO(2) and TD-rCBF responses on the degree of correlation of ORx and FRx. ⋯ ORx and FRx, respectively). These findings suggest that ORx and FRx are subject to temporal latency shifts of ptiO(2) and TD-rCBF in regard to spontaneous CPP fluctuations. Temporal synchronization for the calculation of both ORx and FRx may permit continuous monitoring of these indices with higher sensitivity.
-
J. Neurosci. Methods · Oct 2011
Time jitter of somatosensory evoked potentials in recovery from hypoxic-ischemic brain injury.
Impaired neural conductivity shown by delayed latency and reduced amplitude of characteristic peaks in somatosensory evoked potentials (SSEPs), has been used to monitor hypoxic-ischemic brain injury after cardiac arrest (CA). However, rather than characteristic peak deferral and suppression, the time jitter of the peak in SSEP related with time-variant neurological abnormalities is diminished by the commonly used ensemble average method. This paper utilizes the second order blind identification (SOBI) technique to extract characteristic peak information from one trial of SSEPs. ⋯ Our study is the first application using SOBI detecting variance in neural signals like SSEP. N10 latency variance, related with neurophysiological dysfunction, increased after hypoxic-ischemic injury. The SOBI technique is an efficient method in the identification of peak detection and offers a favorable alternative to reveal the neural transmission variation.
-
J. Neurosci. Methods · Sep 2011
Comparative StudyLentiviral vectors express chondroitinase ABC in cortical projections and promote sprouting of injured corticospinal axons.
Several diseases and injuries of the central nervous system could potentially be treated by delivery of an enzyme, which might most effectively be achieved by gene therapy. In particular, the bacterial enzyme chondroitinase ABC is beneficial in animal models of spinal cord injury. ⋯ In animals which received a simultaneous lesion of the corticospinal tract, the vector reduced axonal die-back and promoted sprouting and short-range regeneration of corticospinal axons. The same beneficial effects on damaged corticospinal axons were observed in animals which received the chondroitinase lentiviral vector directly into the vicinity of a spinal cord lesion.