DNA microarray unravels rapid changes in transcriptome of MK-801 treated rat brain

Figure 1 Experimental strategy and design to investigate the MK-801 effects on rat brain. Details are mentioned in the Materials and Methods section.

Figure 2 Total RNA quality and quantity check, and reverse transcription-polymerase chain reaction. Total RNA quality was confirmed spectrophotometrically (A) and by formaldehyde agarose-gel electrophoresis (B). Stable expression levels of GAPDH and β-actin genes are shown (C). For further details, see the Materials and Methods section. GAPDH: Glyceraldehyde-3-phosphate dehydrogenase.

Figure 3 Reverse transcription-polymerase chain reaction analyses of Cyr61 and Amy1 genes that are differentially expressed in the six (6) brain regions by MK-801 treatment. For the stable expression levels of GAPDH and β-actin genes, please see Figure 2C. For further details, see the Materials and Methods section. GAPDH: Glyceraldehyde-3-phosphate dehydrogenase.

Figure 4 MK-801 increases the power of spontaneously-occurring gamma (30-80 Hz) oscillations. A-B: Typical 2-s bouts of frontoparietal electrocorticogram (bandpass: 20-80 Hz) recorded in a free-moving awake rat under control (vehicle: NaCl, 0.9%, 1 mL/kg, A) and MK-801 (about 40 min after injection, 0.08 mg/kg, B) conditions; C-D: Each chart shows the total power (resolution: 2.4 Hz; average of 8 x 2.5-s epochs) of oscillations during a 90-min recording session, during which the rat received an injection [NaCl (C) or MK-801 (D)] at 15 min (arrow). Note that MK-801 induces a dramatic increase in power, which is still present at the end of the recording session; E: The histogram shows that MK-801 significantly (t-test, ^bP < 0.001) and in a dose-dependent manner increases the power during the 30 to 40 min post-injection period. All values are means ± SEM (5 rats > 100 values/rat, spectral analysis 2.5 s epochs).

Figure 5 Number of changed genes in each brain region and the number of common genes among each region. A: Low-dose of MK-801; B: High-dose of MK-801.

Figure 6 Functional categorization of the differentially expressed amygdala genes based on Gene Ontology. Changed genes divided into 38 function categories in the amygdala.