Localization of hemoglobin (Hb) immunoreactivity in brains of APP/PS1 transgenic (Tg) mice.

<p>Double immunofluorescent micrographs reveal the presence of Hb-β⁺ stains in Aβ⁺ amyloid plaques and some brain cells. Scale bars: 50 µm. Examples of enlarged micrographs are shown in the right. Arrowheads point to Hb-β⁺, but APP/Aβ⁻ cells; while, arrows show APP/Aβ⁺, but Hb-β⁻ cells.</p

Data_Sheet_1_Medial and dorsal lateral septum involving social disruption stress-primed escalation in acid-induced writhes.docx

IntroductionStress may cause prospective escalations in abdominal pain magnitude and accumbal TRPV1 expression, while central neural circuits mediating these stress effects remain unclear.MethodsUsing retrograde tracing methods, we first demonstrated the existence of a medial septal-dorsal lateral septal -accumbal circuit very likely involving social disruption stress-primed escalations in acid-induced writhes and accumbal TRPV1 level. An intersectional viral strategy and virus-carrying hM3Dq and hM4Di DREADDs were, then, employed to selectively modulate GABAergic and cholinergic neuronal activity in medial and dorsal lateral septum.ResultsExciting medial septal GABAergic neuron was found to prevent social disruption stress-primed escalations in acid-induced writhes and accumbal TRPV1 and PKCε expressions. Likewise, inactivating dorsal lateral septal cholinergic neurons was also effective in abolishing these stress-primed escalations. Inactivating GABAergic neuron in non-stressed animals’ medial septum was found to reproduce the stress-primed effects in causing heightened acid-induced writhes and accumbal TRPV1 and PKCε levels.DiscussionThese results, taken together, prompt us to conclude that social disruption stress may produce plastic changes in a newly-identified medial septal-dorsal lateral septal-accumbal circuit. Moreover, medial septal GABAergic hypoactivity and dorsal lateral septal cholinergic hyperactivity are, at least, two likely causes reflecting such stress-produced escalations in abdominal pain magnitude and pain transduction-related protein over-expression in nucleus accumbens.</p

Heme is the Aβ binding moiety of hemoglobin (Hb).

<p><b>A</b>) Interactions between Aβ and various part of Hb. <b>B</b>) Hemin induced the Aβ oligomerization in a dose-dependent fashion. <b>C</b>) Hemin induced the Aβ oligomerization in a time-dependent fashion. Incubation times: 0, 6, 24 hours. <b>D</b>) Aβ binds to Hb, myoglobin (MyoG) and cytochrome C (CytoC).</p

Correlation between potentiated startle and P_CS/P_A (testing) values.

<p>P_CS/P_A (testing) values were obtained by measuring the 3-s averaged BP values before and after the light (CS) during the testing session (averaged 10 times of the CS-evoked response for each rat, n = 12).</p

Blood Pressure Variations Real-Time Reflect the Conditioned Fear Learning and Memory

<div><p>The conditioned fear learning and memory occurs when a neutral conditioned stimulus (CS) is paired with an aversive unconditioned stimulus (US). This process is critically dependent on the amygdala and inevitably involves blood pressure (BP) alterations. We hypothesized that BP variations could instantaneously reveal individual steps during conditioned fear learning and memory. An implanted telemetric probe was used to monitor the BP real-time in rats during training and testing sessions of the fear-potentiated startle. Our results showed that (i) the conditioned fear learning during the training sessions was reflected by light (CS)-induced rapid BP elevations and by electric shock (US)-evoked sympathetic tone elevations; (ii) these two BP-related parameters were not only negatively correlated with each other but also coupled to each other in the training session trials; (iii) both parameters closely predicted the performance of fear-potentiated startle on the next day; and (iv) although local blocking of one of the two fear-conditioned pathways in the training session partially inhibited fear learning, the fear memory retrieval still used both pathways. Altogether, real-time blood pressure variations faithfully revealed the critical steps involved in conditioned fear learning and memory, and our results supported a coupling between the cued learning and the post-shock calmness.</p> </div

Interaction between hemoglobin (Hb) and Aβ.

<p>Freshly dissolved Aβ peptides (50 µM) were incubated with an equal mass of Hb (3.5 µM) at 37°C for 0, 1, 3 and 7 d. <b>A</b>) Aβ_1–40; <b>B</b>) Aβ_1–42. Left panels, anti-Aβ; right panels, anti-Hb-β chain.</p

Data_Sheet_1_Effects of Septin-14 Gene Deletion on Adult Cognitive/Emotional Behavior.docx

While various septin GTPases have been reported for their physiological functions, their roles in orchestrating complex cognitive/emotional functions in adult mammals remained scarcely explored. A comprehensive behavioral test battery was administered to two sexes of 12-week-old Septin-14 (SEPT14) knockout (KO) and wild-type (WT) mice. The sexually dimorphic effects of brain SEPT14 KO on inhibitory avoidance (IA) and hippocampal mGluR5 expression were noticed with greater IA latency and elevated mGluR5 level exclusively in male KO mice. Moreover, SEPT14 KO appeared to be associated with stress-provoked anxiety increase in a stress-related navigation task regardless of animals’ sexes. While male and female WT mice demonstrated comparable cell proliferation in the dorsal and ventral hippocampal dentate gyrus (DG), both sexes of SEPT14 KO mice had increased cell proliferation in the ventral DG. Finally, male and female SEPT14 KO mice displayed dampened observational fear conditioning magnitude and learning-provoked corticosterone secretion as compared to their same-sex WT mice. These results, taken together, prompt us to conclude that male, but not female, mice lacking the Septin-14 gene may exhibit increased aversive emotion-related learning and dorsal/ventral hippocampal mGluR5 expressions. Moreover, deletion of SEPT14 may be associated with elevated ventral hippocampal DG cell proliferation and stress-provoked anxiety-like behavior, while dampening vicarious fear conditioning magnitudes.</p

Pharmacological interventions to locally block one or both of the fear learning pathways and the consequences on the fear-potentiated startle.

<p>The blockers were locally injected into BLA, CeA, MeA or VMH to block local neuron activity before training session. Results were analyzed by Pearson's correlation analysis for individual group. Panels with line marks indicate significant correlation between the ordinate and the abscissa. Results from measuring P_CS/P_A values in the training session indicated that the MeA/VMH-mediated fear learning pathway, but not the CeA-mediated pathway, was BP-related (A–L). However, local blockages in CeA, MeA, or VMH all retained partial fear learning and memory (M–P).</p

The distribution of hemoglobin (Hb) immunoreactivity in inferior temporal gyrus of post-mortem human brain.

<p>Hb-β⁺ stains are present in most NeuN⁺ neurons and OSP⁺ oligodendrocytes; while only a small fractions of GFAP⁺ astrocytes and Iba-1⁺ microglia express Hb. Scale bars: 10 µm.</p

Effects of Aβ on hemin induced cytotoxicity.

<p><b>A</b>) Differentiated neuroblastoma cells, SH-SY5Y, were treated with different doses of pre-incubated Aβ_1–42 without (open bars) or with 0.25 µM of hemin (closed bars). <b>B</b>) Differentiated SH-SY5Y cells were treated with different doses of hemin without (open bars) or with 0.25 µM of pre-incubated Aβ_1–42 (closed bars). The cell viability was determined by MTT reduction assay. Bonferroni's post-hoc test: * <i>p</i><0.05 vs. respective hemin group.</p