## 1 Introduction  
The mammalian brain is sub-divided into numerous regions, each with a specific physiological function. Dissection down the midline identifies the two most visible features--an interior core of white matter (WM), composed of phospholipid rich myelinated axons, and an exterior layer of gray matter (GM), composed of arborized neurons with un-myelinated axons [1]. Due to the brain's complexity, there remains an important need for novel technologies that further delineate the (sub-) cellular components, in order to monitor and characterize the bio-chemical changes associated with neurological dysfunctions. The drawbacks of the current bio-diagnostic technologies are that they are too time-consuming, provide low resolution, and alter tissue integrity. Current imaging techniques, such as positron emission tomography (PET), magnetic resonance imaging (MRI), and computerized tomography (CT), are used to identify disease pathology. CT imaging is rapid, highly reproducible and low in cost for clinical brain-injury screening. However, it is not equipped to detect all types of lesions in the brain, specifically, those related to the development of the secondary injury. MRI has long been the gold standard to study changes in gross brain morphology, and has been routinely used to examine the peri-infarct zone, following a stroke. Unfortunately, MRI does not have sufficient spatial resolution to study individual cells within the brain and reveals little information on the biochemical mechanisms of tissue insult [2]. Infrared (IR) spectra originate from the vibrational motions of atoms, in chemical bonds [3]. As the molecule absorbs the electromagnetic radiation, it produces a band in the IR spectrum, at specific frequencies [4]. The IR spectra vibrational frequencies provide information about chemical compounds, including bio-molecules, and produce characteristic fingerprint for proteins, lipids, cholesterols, phospholipids, carbohydrates, and nucleic acids, as well as providing a unique biochemical and biophysical fingerprint for the sample [5]. Fourier transform infrared (FTIR) spectroscopy is a simple, sensitive, accurate, highly-reproducible, non-destructive (with respect to sample preparation), and rapid, diagnostic technique [6]. In contrast to the standard histological staining methods, FTIR is the \"state-of-the-art\" bio-diagnostic and bio-imaging technology for fast diagnosis in medicine and biological studies. It has been used to screen and characterize a wide range of tissues and organs [7; 8; 9]. FTIR imaging spectroscopy has also been used to analyze the pathological changes associated with stroke, traumatic brain injury (TBI), and neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS) [10; 11; 12]. We report here that FTIR technology is relatively straightforward and rapid. There is no requirement of prior treatment of brain samples with dyes, or reagents, in order to characterize the different brain structures, and the technique, in addition, is non-destructive, which allows the sample to be analyzed with additional techniques. Hence, FTIR can be a fast, reproducible technique, in order to characterize the biochemical make-up of various brain regions, to provide a good platform for investigating brain alterations at the molecular-level, such as in the cases of neurological disorders. Furthermore, a combined analysis of FTIR and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) imaging can improve the brain tissue elemental characterization and classification, expediting the diagnostics and therapeutics. LA-ICP-MS has been shown to be a powerful technique for brain tissue imaging [13; 14; 15; 16; 17]. One disadvantage is that it is a destructive technique but, in combination with FTIR, the same sample can be analyzed to overlay the information of both techniques and can show changes, especially with respect to diseases, in the aging of brains.