Learning and memory assessed by fear conditioning and water maze tests.

<p>A) Fear conditioning: percentage of freezing in the context and cue tests of memory 24 hours after conditioning. Single-housed mice displayed reduced freezing in both tests, animals from cages enriched with nest material showed reduced contextual freezing. B) Escape latency during learning of initial, reversed and visible platform positions. C) Percentage of time spent in the target zone and in respective zones of remaining quadrants during transfer tests. Transfer test 1: enrichment with nest increased the time spent searching at the trained zone. Transfer test 2: single-housed mice without nesting material showed no preference to any zone. D) Percentage of time in thigmotaxis during transfer tests: nesting material reduced thigmotaxis.</p

Body weight, motor and sensory functions.

<p>A) Gain of body weight: single-housed mice had increased body weight irrespective to enrichment. B) Motor learning and coordination: latency to fall from the accelerating rota-rod was not affected by different housing conditions. C) Pre-pulse inhibition: percentage of PPI at different prepulse intensities was not affected by different housing conditions.</p

Immunofluorescent colocalization stainings of TMPAP and synaptic vesicle associated proteins.

<p>TMPAP (green) is colocalized with a presynaptic marker, synaptophysin (red) (A–C; yellow color and white arrows depicting the colocalization). PAP was seen in vesicle-like structures that had strong colocalization with Snapin (D–F). Small picture is a magnification from panel C, depicting the colocalization. Moreover, largest PAP-immunoreactive structures had a colocalization with multivesicular bodies (MVB, red; G–I). All pictures are from striatum. Scale bars are 10 µm in A–C and G–I, and 3 µm in D–F.</p

The colocalization of PAP (green) and GAD65/67 (red) was seen in several areas of brain.

<p>In cerebral Purkinje cells (A–C), strong colocalization was seen especially in the axon hillock of the neuron (small picture in C; yellow color and white arrows depicting the colocalization). Similarly, PAP was present in GABAergic neurons in prefrontal cortex (PFC; infralimbic cortex) (D–F). Scale bars are 10 µm.</p

TMPAP is expressed in the mouse brain and colocalizes with GABAergic marker, GAD 65/67.

<p>Representative confocal images depict intense TMPAP (brown color) expression in molecular cell layer (M) and Purkinje cells (P) of cerebellum (Panel A), in substantia nigra pars reticulata (SNpr; Panel B), in red nucleus (RN; Panel C) and in oculomotor nucleus (O; Panel C). Small picture in Panel B depicts the TMPAP staining of the substantia nigra in PAP<i>^−/−</i> mouse. TMPAP (green) was colocalized with GABAergic marker (red) in medium spiny neurons of striatum (Panels D-G, yellow color and white arrows indicating the colocalization) and in SNpr (Panels H–K). Colocalization was evident also in GABAergic neurons of hippocampus CA1 (Panels L–O). DAPI (blue color) was used as a nuclear marker. Scale bars are 500 µm in Panels A–C, and 10 µm in panels D–O.</p

Immunostaining of Snapin in various brain areas of WT and PAP^−/− mice.

<p>In the PAP^−/− mouse, Snapin (red) is localized more diffusely in the cell soma (B, D, F). Cellular localization of Snapin in WT mouse is more vesicular-like (A, C, E). Scale bar is 10 µm in all figures. M1 - primary motor cortex; SN - substantia nigra.</p

Anatomical, neurochemical and behavioral characterization of mice deficient in prostatic acid phosphatase (PAP).

<p><b>ABBREVIATIONS:</b> NSD - no significant difference; ↑- increased; DA - dopamine; DOPAC - 3,4-Dihydroxyphenylacetic acid; GABAA - GABAA receptor; mIPSC - miniature inhibitory postsynaptic current; LORR - loss of righting reflex; PPI - prepulse inhibition; EPM - elevated plus-maze; OF - open field; LD - light-dark box; RR - rota-rod; BW - beam walking; FST - forced swim test; TST - tail suspension test; FC - fear conditioning; RI - resident-intruder test; WM - water maze.</p

Dopamine synthesis is augmented in the striatum of PAP<i>^−/−</i> mice.

<p>(A) Tissue levels of DA are similar in WT and PAP<i>^−/−</i> mice. (B) Level of the principal metabolite of DA, DOPAC, is elevated in the PAP<i>^−/−</i> mice, and also the DOPAC/DA ratio is elevated (C). (D) Accumulation of L-DOPA is greater in PAP^−/− mice than WT mice 30 min after administration of a blocker of L-amino acid decarboxylase, indicating increased DA synthesis. The data is expressed as mean±S.E.M.; black bars represent WT, grey bars PAP^−/− mice; *<i>p</i><0.05, two tailed t-test (monoamines) or repeated measures ANOVA (microdialysis).</p

Lateral ventricles volume is enlarged in PAP^−/− mice.

<p>Lateral ventricles (right and left ventricles) volume is significantly larger (**<i>p</i><0.01) in both young and old PAP<i>^−/−</i> mice compared to corresponding WT mice. (A) T2-weighted images from young (2 months) and old (12 months) WT and PAP<i>^−/−</i> mice. Plot of (B) lateral ventricle volumes and (C) total brain size for WT and PAP<i>^−/−</i> mice. The data is expressed as mean±S.E.M.</p

Characterization of dopaminergic transmission in PAP^−/− mice by microdialysis.

<p>(A) There is no difference in haloperidol (0.2 mg/kg) -induced dopamine release between PAP^−/− and WT mice. (B) Adenosine A₁-agonist GR79236X (1 mg/kg) and A₁-antagonist 8-CPT (300 µM in dialysis fluid) significantly decreased and increased the release of dopamine, respectively (repeated measures ANOVA) but there was no difference in the magnitude of response between the genotypes. (C) There is no significant difference in potassium–induced DA release between the genotypes, but amphetamine induces DA release significantly faster. The data is expressed as mean±S.E.M.; black squares represent WT, grey dots PAP<i>^−/−</i> mice.</p