Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) offers a high degree of spatio-temporal resolution and has become a vital tool for the investigation of brain function. A positive BOLD response occurs in response to ...

Histologic methods has long been used to examine tissues /organ systems for potential morphologic changes. However, the detailed examination of structures such as axon tracks, which can exhibit complex three-dimensional (3D) morphologies and cover significant distances, can be difficult to accurately determine using these methods. In order to gain a clearer understanding of morphologic ramifications which may occur following random or targeted genetic modification of specific murine lineages, we are developing MRI scanning and data analysis protocols which allow us to determine, in a relatively high throughput manner, changes in neural tracts within the murine CNS. In order to determine the practical limits of morphologic resolution using these MRI scanning and analysis protocols, we examined several axon guidance mutants previously characterized in our laboratory. The mutants examined represent members of the EphB family of receptor tyrosine kinases. T2 weighted multiple spin-echo images (TR 1500 ms, TE 3...

Brain fetal anatomy has been previously studied using echography , 2D MRI and post-mortem pathological examination. Fetus brain 3D MRI can offer a new perspective to study in vivo early stages of cerebral morphogenesis. Therefore, we performed MRI studies in five fetuses aged from 27 to 40 gestational weeks. The MRI was requested for medical reasons. MRI acquisition was performed on a 1.5 Tesla GE with the parameters: Fast Spin Echo T2, TR = 8000, TE = 120, voxel size: 1.4 x 1.4 x 4 mm. Acquisition time was about 2 minutes. No morphological pathology was detected. A semi-automatic cortical mantle detection was applied using a spherical deformable model whose deformations are driven by the contrast between CSF and gray matter. This procedure allows an anatomical 3D coherent reconstruction. An automatic curvature-based recognition of each sulcal roots was performed in each fetus brain and yielded a clear understanding of the dimples that mark the first stages of sulcal folding. The obtained 3D primal sketche...

Rationale: Mesenchymal stem cells (MSCs) represent a promising clinical therapy for ischemic stroke; however, critical parameters, such as the most effective administration route, remain unclear. Intravenous (i.v.) and intraarterial (i.a.) delivery rout...

The neurotransmitter dopamine (DA) has received special attention because of its roles in reward behavior and the control of movement. The relationship between DA release and broader circuit function is complicated by the diverse modulatory roles of DA ...

Regulation of dopamine release and synthesis is thought to occur via pre-synaptic dopamine(DA) D2 autoreceptors. Selective mapping of autoreceptors in vivo is difficult, as their function is best assessed using dynamic measures of DA release such as microdialysis. We show here that pharmacologic MRI (phMRI) may also prove useful for this purpose. First, we mapped the phMRI response to acute agonism and antagonism of D2 receptors using either quinpirole or eticlopride. These ligands lead to small change in relative cerebral blood volume (rCBV)(<10%) in stiratum (Str), nucleus accumbens (NAcc), and cingulate cortex. We then studied the response to an amphetamine (AMPH) challenge using pre- and post-treatment with eticlopride and quinpirole. Agonism of D2 receptors using quinpirole lead to a large decrease in rCBV changes induced by AMPH in Str and NAcc, but had little effect in frontal cortex (FCtx). Conversely, antagonism of D2 receptors with eticlopride lead to a large potentiation of rCBV changes induced ...

Optimizing neural stem cell (NSC) delivery procedures is critical to the success of cell therapy. Unlike small molecules and growth or neurotrophic factors, cells are sensitive to their host microenvironment. Cell injection variables, such as flow rate,...

Multimodal imagining approaches are frequently used to address the neural changes associated with alcohol use disorder (AUD). Combined imaging techniques, such as magnetic resonance spectroscopy (MRS) and diffusion weighted imaging (DWI), may provide co...

Prior research suggests that the neurobiological underpinnings of depression include aberrant brain functional connectivity, neurometabolite levels, and hippocampal volume. Chronic restraint stress (CRS) depression model in rats has been shown to elicit behavioral, gene expression, protein, functional connectivity, and hippocampal volume changes similar to those in human depression. However, no study to date has examined the association between behavioral changes and brain changes within the same animals. This study specifically addressed the correlation between the outcomes of behavioral tests and multiple 9.4 T magnetic resonance imaging (MRI) modalities in the CRS model using data collected longitudinally in the same animals. CRS involved placing young adult male Sprague Dawley rats in individual transparent tubes for 2.5 h daily over 13 d. Elevated plus maze (EPM) and forced swim tests (FSTs) confirmed the presence of anxiety-like and depression-like behaviors, respectively, postrestraint. Resting-stat...

Objectives: Some traumatic brain injury (TBI) cases subsequently develop epilepsy, and research on antiepileptogenic therapies is hampered by a lack of biomarkers for identifying high risk individuals. This work develops techniques for identifying poten...